Sounds very similar to the way I have ours set up. The distance is no trouble, the whole system relies on the water pressure for the rest of the house, just remember water will take the path of least resistance when it can. The one thing I would suggest is that you use a resivoir for your auto top off, and use a ball valve inline before each float valve, so you will have to manually turn on the water from the RO/DI to fill each resivoir. Research indicates that constant turning on or off for short bursts degrades the RO membrane rather quickly.

But the float valves are great, here's a link to the simplest auto-top off I created using just a float valve and one of those aqualifter pumps, that may be of some use for ideas if nothing else.

http://www.captivereefing.com/viewto...highlight=dato