Actually Carbotech probably has pads for it by now, or either in the very near future. You should give Carbotech a call and see if they have them developed yet. Worst case a few months. This would be a good track setup due to the massive amounts of heat capacity that it gains over the stock WRX setup.
I've done the setup before and I'd do it again given the opportunity.
Soundwave: I don't think they will fit under a 16" wheel at all.