Bilsteins should be good, RSFB ideally or inserts are a must for controlling the rear end. On the street you won't need much else. RSFB and rear roll bar could be done at the same time to save on labor since both require lowering and/or dropping the subframe.
M3 front arms make a big difference from both bushing stiffness and camber, other than that I wouldn't go crazy. Front arms can be done independently as they don't require any disassembly to access.
My priority list would be
- RSFB
- M3 Front Control Arms
- Shocks/Struts