Koni Yellows are still available for the mkiii AFAIK. I autocross my supra and am riding on the standard eibach/tokico blue setup. Its meh, ok for STX. I really haven't come across a good performing coilover setup for our platform aside from the rare bilstein setup. Japanese and the new wave of "tuner" coilovers will more than suffice for daily duties and slamming the car, but aside from that, you could get a better performing setup with Koni yellows, H&R sport springs and a good alignment.
KW suspension is located in Sanger CA, pretty local. Could visit them and see what they could do for you. If not, and you're set on coilovers, Megan seems to becoming very popular. I drove a 240sx with a Megan setup, it wasn't bad.