I'd definitely look into about a 200 to 300 Watt Heater, I'm finding my 300 Watt is a little underpowered for my 75g.
As for wavemakers/powerheads, I like the Koralia ask around for the correct flow that people recommend they come in alot of sizes. I have 2 2's and 2 3's running on the 75g but they are getting replaced with 2 Vortech MP40W's. I saw those wavemakes at a FragFest and they are incredible. If you plan to use a wavemaker i.e., Reefkeeper Lite or other controller to create waves be aware that the Koralia can make alot of noise when starting up and shutting down, another reason I'm switching to the Vortechs.
I built my refugium for my 75g off of a design at
www.melevsreef.com. If your tank isn't reef-ready you'll need an overflow box.
As for keeping the tank cool, you can use a clip on fan to blow air across the water to help with evaporation that will cool the tank. I'm going to wait and see if I need a chiller, I'm running about the same wattage as you for lights.
Other things I'm looking at getting a little later down the road. Automated top-off and maybe a kalk stirrer.
I'm totally a newb so you'll want more guidance, WetWebMedia, Melevsreef and Tampabaysaltwater are some of the sites I tend to read the most.
SB
Oh I did forget to add, read up on plumbing!
Also you can check out some pics of my tanks at
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