I've heard decent things about air water and ice. They are a sponsor here and also sell on amazon. Since it doesn't seem your getting much response from anyone but me, it might be worth posting in their sponsor forum ((
http://www.reeffrontiers.com/forums/181-Air-Water-amp-Ice)) and see if they can help with your questions. If the tap you plan to use has really low PSI you might need a booster pump. They could give you specifics on the numbers on that. They might even be able to look up a water quality report for your locality (or you could) and provide some specific recommendations.
I haven't looked into ro/di's in a long time since I'm 'happy enough' with mine, so other than wanting the water saver (basically just adds another filter so that you don't waste so much water), I don't know what else you should really be looking for. Hard to not want the highest GPD you can afford, just because it takes so long, especially when your hooking up to a sink and monitoring. One tip I have for that part though is to use the bathroom sink, and place the container your filling in the bath tub. Its not cool when you forget you have it running and there is water all over the floor, so, if that container is in the bath tub at least you won't have a mess to clean up...