My Supra has got Koni's and used to run Tokico Lumina's, (a pretty decent replacement for tems, but they tend to blow seals under hard driving), but I've driven cars with Bilstein's and kyb's and they're pretty good.
IMHO Koni Yellows are clearly the best shock out of them all.
As far as coilovers go, unless you've got someone who is an expert to set them up for you and dial them in just right, (which is time-consuming and complicated) you will probably have an expensive disappointment.