personnaly I would take the 325e with the 2.8i stroker conversion....ie. "i" head swap, over just the 325i....the gains are tremendous. check this site for the full details on doing it. Very comprehensive and you can see the gains are amazing. you can squeeze out 180hp 190lbs/ft or add a few more mods and 205HP is what you get. (crank HP) Those are some pretty good gains. not to mention the flatter torque/HP curves.
http://www.strictlyeta.net/technical/328i_1.html