I'm looking to do the same thing. So far, I've gotten the materials and now have to figure out how to put them together. Here's the materials I'm using:
plastic vapour bariour. don't have any water on the concrete floor, but i'd ratehr be safe than sorry.
Treated 2x4x8ft. laying flat on the concrete to save space.
1.5in foam insulation, 4x8 ft. sheets. these are pre notched to cut into 1/2 making 2x8 sheets. i'm planning to cut the width of a 2x4 framing off each half, making the framing 24" on center.
then on top of that i plan to add 3/4inch 4x8 plywood.
i too would like to hear additional ideas and suggestions for basement subflooring....