Not to offend anyone but first of all I would only go with a 2000 and up and secondly I would only go with an S. The pre 2000 models had some "issues" that were worked out by 2000. If I had to get a 2.7 I would go with another car, like an M3 in the same price range or add about 15K and go with a 996 C2.
As far as mods, to each his own I guess so get the car first and see if you get the itch.
Good luck!