The ZHP doesn't use special springs. It uses the same springs as any other 330 with the sport package. You might also read up on some of jpr's threads as I believe the pre-2001 sport package was actually firmer than the post-2001 sport package. If your car came with the sport package, this could potentially be a downgrade for you. If you don't have the sport package, then it might meet your goals. Too hard or too bouncy is too subjective.
If you're replacing shocks, replace the mounts.
04 IR 330i ZHP | ESS TS2+ SC | MagnaFlow "headers" | KMS 3.64 LSD | AST 4100 550/650| APEX ARC-8 18x9 | H&R front sway bar | Vorshlag camber plates, RTAB limiters | TMS subframe & swaybar reinforcements | UUC SSK & DSSR | UUC TM & TME | BW motor mounts | Dinan strut & shock tower bars | vaio 4-bolt oil pump