I just got these:
1)5 lb CO2 tank filled - $64 from local welding store
2)CO2 Reg (Milwaukee) with solenoid, bubble counter, needle valve and some tube - $89 shipped from aquariumplants.com. Basically, they price matched eseasongear.com
Those were the best deals I've seen so far. I still need to order check valve and diffuser (or reactor). I think that's all you need.
55 Gal Tank with: Eheim 2213 Canister, Hydor Inline 300 Watts, 2X54 Watt (6,700K & 10,000K) T5 HO for 7 hrs, Excel for CO2
3 Discus, 4 Mollies, 2 Tetras, 2 SAE, 1 Pleco,1 Platy, 1 Zebra Danio, 1 Snail
1 Cryptocoryne, 1 Java Fern, 4-5 Unknown, Dwarf HG, Some baby tears