go for a 540, add a chip (Mark makes a killer one for it) and dont look back. You WILL NOT have a 1/4 mile killer but will smoke em on the highway. I only have a 530 and havent been smoked by anything from an 80 roll, I mean thats where these cars are prime. I just cooked one of them new Chryler Hursts tryin to pass me on an incline and they had a merge lane, i kept her floored and after 60 it was getting close, they had to back down (I should have shut the air off) hehe screw Hemi... anyways if you look into a 540 or 30 or 35 or whatever do your research. Go check out Brunos site and look things over carefully and DO NOT buy anything without maintenance records! Look out for Nikasil (for others reasons not mine) and last but not least you can always gear these higher for more low end oomph, I did 3:15 to 3:64 and didnt loose an ounce per gallon but have a lot more low end around town and can still bake at blistering speeds cross country.
95 E34 530I V2.37
===========
Those who make peaceful revolution impossible will make violent revolution inevitable.
John F. Kennedy