H&R Coilovers - $1200.oo www.bavauto.com
Bilstein PSS9 w/ 9 adjustable shocks - $1499.95
Bilstein PSS - $1149.95
(off the top of my head)
The reason you would have a negative/ higher ride height after purchasing your springs is bc your stock sport package is prolly lower than those springs. So getting some aftermarket springs would only heighten your ride height.
But if you want a more aggressive stance/look and better handling, go with the full shock tower setup. where the coilover is embedded as part of the shock tower and not some slipover metal sleeve.
Im going to get the H&R Coilovers for my 04 325i. although it fits all e46's except xi's.
if you do go with evolutionsports, give me an email so ill tell them that im sending you through, theyll give a small discount or free strut bar.