Get $500 Racelands shipped to your door, It will save you the issue with springs and stock shocks. Sounds like you want the look anyway Raceland coilovers do that for you. I Currently have the installed on my sedan. You can also take a look at Rokkor Racing Affiliate's of Raceland from what i understand.
http://www.racelandus.com/p-58-coilo...r-bmw-e46.aspx
http://www.rokkortuning.com/p-21-coi...r-bmw-e46.aspx