congrats dude, space grey ftw!!
black out the 335i rear badge while you're at it :-)
I think the max you can go without rubbing (depending on the offset of your wheels) is 265. As for the exhaust, grab a PE if one ever goes up for sale here... definitely worth it.
2015 BMW M3 (ED 03 Nov 14) /l\ Austin Yellow /i\ 6MT /l\ Exec Pkg /i\ HK Audio /l\ 437MCCA Member