I like Pablo's idea about the 1M...but a 335 would be much more practical for it's larger size. My co-worker has a new 335...and I thought the MS3 had low-end torque!!! His 335 has s*** loads of torque from 1500/2000 RPMs. It's a fun as hell car, but it's no M3. The only problem with the new BMWs is that it's not cheap haha.
Maybe you should wait until Mazda announces the replacement for the RX8? Assuming you want to stay Mazda. Also, there's some really cool RWD coupes coming out in the next year or 2. There's the Toyota FT-86 and the Subaru BRZ.
Damn Josh!!!! That looks like you guys did a really good job.
Phen, have you thought about going back to stock with the MSM? I'm not sure how much you've done though, so that might not be easy.