I ran 30mm lowering springs with standard shocks and changed them after 3 weeks, it felt downright dangerous. I then stuck a set of JOM coilies on which have been fine for about a year.
I'm getting a bit tired of the bumpy ride now though, looking at a set of KW V1's instead.
The point I'm trying to make is, buy cheap, buy twice. Get the best you can afford otherwise you'll regret it.