Top of the line are something like Tein, Apexi maybe Progress w/ threaded shocks. Unless you're making a 1g+ skidpad monster, Skunk2 or Ground Control will do but you'l probably need some new shocks later on. (Of course, you'll need shocks anyway with lowering). If you're dirt cheap, then go with Ractive or Arospeed.
Overall, I'd pick Ground Control over Skunks because they use Eibach and they come in a variety of spring rates. Pretty much, Skunk2s and GCs are the Hondas of coilovers. I just don't see the point of spending more than a g for coils in a car that's worth less than 20k.