I race on the saturdays on a polished wood floor. I found that the best setup is the same as usual, I don't change absolutely anything and it works like a dream, but there is some grip once we starts qualifying (some ppl even grip roll !).
We use the schumacher rally blue (there's a schumacher series for which it's the controlled tyre) and as Sosidge said, it's like on wet conditions : narrower you'll have more grip, but they'll wear fast, wider you'll have less grip but they'll last longer.
Anyway, I've raced on a polished concrete floor (and won
), my setup was very soft in springs, a lot of droop and the rest was normal. Don't go on exotics setups, stay on basic values for toe in, camber, etc, and try to find the best tyre/springs.
On that race, I used the Tamiya M2 grip tyres, with hard inserts on front and foams on rear, and TC2 additive (it was allowed and once the floor cleaned, worked like a dream, water instead of additive also worked on that strange surface when it was still dirty).
Hope this helps...