You can't go wrong with Eibach prokit or Espelirs. For stiffer springs, Teins are good. It really depends on what you are looking for (street or track) and how low you want to go.
I prefer the sprint springs, they have a very aggressive 2 in drop but the sprints which im running now are much stiffer then any lowering spring ive experienced, I like them alot better, and they were very inexpensive.
