We are treating the concrete slab in a house we just bought by bleaching the floor and then painting with Kilz sealer. We recommend the Oil-based original version (~$10 gallon). The two rooms we have treated (2 coats) have turned out fine. We will also get the odor-ban--thanks for the tip!
P.S. To the last poster: Comments like that don't help anyone else out; if you want to vent your own biased view, do so with your friends, not in public.