ok.
for the ultimate indoor field, you can purchace artificial grass outdoor carpeting which can be glued directly onto the cement floor. It won't be cheap, but with a little paint on it, you will slide nicely on it. I'd imagine if you bought the carpet on the roll, and laid it your self, it wouldn't be too bad price wise, and would probably compare with sand.
As for fixing your supair baracades, i sugest two things. Depending on what type of barcades you have, you can use water or sand.
If you have the fan powered ones, they should zip open, and you can place the sand bags around the outside edges, and then zip them back up.
If you have the perminantly inflated ones, (with the bung) then you inflate them, and fill the bottom few inches with Water. You may also want to place sand bags around the base to hold them in place, and i'd also sugest slightly under inflating them so that the whole base stays on the ground. With a few inches of water in the bottom, even the fattest git won't be able to knock one over.
Good luck, and post pictures when you are done.