Heres a list of what I use for my 55g reef, it's simple, cheap, not the best products but they work for me.
55g glass tank
54w x 4 T-5 lighting (decide what corals you want before buying your lighting, I had to buy another light since my first buy wan't enough.)
Cap1800 return pump (low flow from the refugium but I do that intentionally)
external overflow box (u-tube style)
SeaClone 150 (works for me, but not recommended, you'll wind up having to get a better unit later on.)
I built my own 10g sump/refugium and stocked it with aquapods, tigger pods, and cheatomorphia. restocked with gammarus shrimp (scuds) from another tank I had.
Other than that, I use only 1 powerhead, a powersweep. Not a good buy either.
you can see alot of what i use is crap gear but my water quality stays optimal , aside from not having an auto top off system. And I get compliments constantly about how good the tank looks. It still looks like a mini-frag tank to me, but I stare at it constantly.
I'll second melev's site, source of some good information. As well as Travis's Starting a Marine aquarium log, he's also the guy who I learned to build my cheapo 10g refugium for about $40 bucks. and most that cost was the tools need that i can use again and again.
Everybody here said it best: READ, READ, and then RE-READ. I can't tell you the amount of livestock i bought only to find out that a certain fish isn't compatible, or a certain coral cannot handle the light intesisty i'm using.
At least you came here to ask, instead of asking LFS's, I find alot just want the money! "sure that shark will go just fine in your seahorse tank."
Best of Luck!!!!
