If you want to do a floating floor, you could glue a very thin plywood/leuon to the 9x9 tiles as to not disturb the asbestos. Then lay you're vapor barrier on top of that, followed by the floor covering itself. Floating floor over a concrete slab should not be an issue so long as the vapor barrier is sufficient, installed properly, and the slab is not saturated at the time of installation. Also, those old 9x9's will likely break up some while you're working regardless of what you cover them with. I think that the leuon would help distribute the weight and prevent excessive cracking in the tiles as well.
FYI - Not sure about your state/local laws, but the EPA doesn't care about someone disturbing asbestos in their own home. Furthermore, 9x9 tiles can typically be removed "non-friable" so long as you can lift them without destroying. Let me know if you'd like any more info on that and I'd be glad to shoot some over.