I'm on 14's. Perhaps getting springs/shocks would be a good idea. It would look nice by eliminating some nasty nasty wheel gap. Also, since my clutch grabs so hard, when I shift, the back of my car slams...so if I had stiffer suspension, I suppose it would help with that. Cuz I've been wanting to lower my car but favored going the performance route more, but with springs/shocks I can do both
I just got my tires and they actually grab good, so I won't be looking for new ones for awhile. It looks like now I'm probably going for exhaust, then a decent suspension set-up, maybe KYB and H&R or something like that.