Looks like you've got a good plan going for your upgrade. I'm jealous.
Where is your tank going to be located?
I see that you're in California. I understand the electrical prices are rather high. Have you looked into LED's for lighting? The upfront cost would be high to light your tank.
However you would be saving money pretty quickly and would recoup the cost in much shorter time than I would out here in StL.
LED's are powerful enough now to penetrate to the bottom of 24 inch deep tanks, and you are planning on a sand bed. So you actually have less depth to go.
LED's are lasting 50K hours, at 10 hour long photoperiods, that's going to be 13.698 years, (13.7 rounded), with 12 hours photoperiods that's going to be 11.415 years of run time.
That's 11-13.7 years without replacing a bulb.
So whatever you're paying for electrical useage, you need to figure out the cost to run three 250 w MH's monthly, plus the cost to replace whatever bulbs you wanted to run yearly.
48" 4x72W AquaIllumination Modular LED Light System
Thats for the Blue, personally I'd go white, but it doesnt appear to be on Premiums website at the moment. These are the AI Sol's, the Phoenix should be out sometime soon and is reported to be less expensive. These are not cheap, and its for 48 inches worth of lighting as opposed to 60. I figure you should get your foot in the door, and then add another one if you need/it want it then.
With this set up you'd be using 288 watts of main (as opposed to supplemental like T-5s etc) instead of 750 watts.
Another option right now is the
EcoTech Raydion XR30W.
You would need a minimum of 3 of these, possibly 4, and they can consume as much as 118 watts per fixture, so 354 watts as opposed to 750. But that's only if you're running it on high with all LED's lit. This is designed to be easily programable to change colors to suit your tastes and every case I read where people have switched from MH's to LED's has had to drop the LED intensity down to 50% because they are bleaching their corals. The white, blue and royal blue LED's are all within the narrow band of light spectrum that corals use for photysnthesis. This means that ALL of the light produced by those LED's is useable to the corals. With MH's, the light produced is not just within those narrow useable wavelengths, so there is light produced that cannot be used by the corals, (wasted). The LED's arent doing that, hence the corals being bleached.
Things to Beware of when changing to LED's This explains it better than I can. Full disclosure, I'm a mod on that board, but this is the best way I've seen yet that explains why corals are bleaching when people switch over to LED's from MH's....
The Raydion has both red and green LED's that can be turned on and tailored to meet your aesthetic needs for your tank...
Another option if you cant afford the out of the box systems, (I cant, I'm currently running 250 W MH's on my system too) is to DIY them. I'm looking more at this route myself....Here is one place you can go to DIY them...
http://www.rapidled.com/servlet/StoreFront
I've never DIY'd lighting, but in poking around the site, it appears to be pretty simple...big savings that way.
Also regarding your QT plans....I would suggest not using cupramarine unless absolutely necessary. Even chelated copper is harder on fish than a hypo salinity treatment. Here is another link to that board. Lee Birch is phenominal with fish diet, nutrition, and health....
Curing Fish of Marine Ich . I've used the hypo salinity method he outlines there several times with new fish. I havent lost one yet and its less stress on the fish.
I simply use a Kalk dripper and fill it with RO water that has had sodium bicarbonate added to it, get a pH monitor calibrated, and start the drip. A slow drip with sodium bicarb laced RO will keep pH up, (hypo saline water has unstable pH issues), and keep salinity at the desired level for the duration of the treatment. You should also know that if your fish have ever had ich, it will be eliminated from your system after awhile due to the fish developing stronger resistance to it. If its been a year or longer without ich showing in your tank, you dont have it anymore as long as you havent added any new fish, corals, or inverts. That's right, fish, corals or inverts...ich can hitch a ride in with these things. So plan on QT'ing everything you put in the tank for at least 6 weeks before moving it over to your display system.
Dont get me wrong, I'm a huge proponent of QT'ing your fish and inverts to avoid introducing new diseases and to acclimate your more delicate critters to a captive environment, but realize that its very difficult to be 100% effective at keeping ich out of your system. I've gotten to a point where I QT fish for a period of approximately 6-8 weeks to get them eating prepared foods in a safe environment, (no bullying etc) and then I move them over to my system. This reduces the chances of things going bad and gives the fish the best chance possible at acclimating to my system. But I also have a small ich bout going on in my system right this very now. When I say small, I mean one fish is showing one or two spots of ich and has been for about a week. My system is a 120 display, with a 58 satellite tank, a 75 gallon sump,(50 gallons in sump, extra space for errors or general unplanned events, like power outtages), and a 40 breeder frag tank. Total system volume is about 250 gallons. My system contains the following fish:
4 inch Indo Pacific Regal angel (in my care 4 years this month, housed in 120)
4 inch Tomini Tang, (also 4 years this month, housed in 120)
2.5 inch Purple Tang, (also 4 years this month, housed in 120)
3 inch Black Cap basslet, ( 2 years in my care, no idea which month, housed in 120)
Mated pair of Rod's Onyx Clowns, (7 years for female, 5 years for male, housed in 120)
Bonded pair of Picasso Percs, (3 years in my care, housed in 58)
Firefish (3 years, housed in 58)
1.75 inch Blueline Angel, (3 months, showing ich, still eating and behaving normally. Havent seen more than 2 spots of ich on him thus far, housed in 58)
3 inch Powder Blue Tang, (3 months in my care, housed in 40 frag tank no signs of ich, and will not be staying in the 40 breeder long).
Since all of my fish were QT'd before going into my system, I can only guess that I introduced ich into my system by adding some sort of invert. I dont currently QT them. But I will when I upgrade in a couple of years to a tank with similar dimensions to yours.
Sorry for the ridiculously long post. You asked for opinions and well....you asked for it...
Looks like you've got a good set up planned out. Congrats.
Nick