I bought a 110gpd unit off ebay a couple of month ago, it came with a drinking water kit, I have been very happy with it, cost 130.00 shipped, the sell a buy it now for 135.00 shipped, seller is filtersdirect.
I got mine at Lowes for $170. 5-stage, 3 gallon holding tank, drinking faucet hook up. I installed myself. Took about 3 hours. I upgraded the membrane to 100 gpd bought from inreef.com for $35.HTH.
-RY