I just bought a bunch of stuff from these two places to convert a vintage Westinghouse fridge (circa 1950). I searched around for what I wanted and split the order due to some things being better priced at one or the other. For what I wanted, these two places had the best prices.
From Keg Connection I bought the 2 tap fridge conversion kit with two line distributor and Perlick 630SS's, a gas line extension kit for a 3rd keg and a party faucet/line/disconnect.
From AIH, I got a 10 lb CO2 tank, three 5-gal pinlocks, one 3-gal pinlock, keg faucet adapter (a faucet to fit on the 3-gal corny with a pin lock disconnect), CO2 keg charger for the 3-gal with 3 extra 16g CO2 cartridges for the 3 gal corny, and 3 sets of O-rings. I plan on using the 3-gal corny for tailgates, parties, etc. and wanted easy portability.
Everything was under $500 delivered. If you want the basic kit to convert a fridge/keezer, Keg Connection could set you up for under $300 with the CO2 tank.
I'd recommend looking at various sites based on what you want.