06 or 07's make no difference on the e86m. 03 996's are not desirable to me in anyway, but I did have a 997, which I traded for my e85. If your into bragging rights and all out speed stay away from the euros. I'd get a c6 vette in that price range.
e86m or cayman s for me. maintenance and repairs are cheaper on the bmw though. drive them both and let that decide
F80 m3, 997 gt3, 14 ram ctd, f15 x5, drz400sm
Gone:z4m, boss 302, c6 z06, m6,z3m