Really comes down to how much power you want to make and how much money you want to throw into a fwd Grand Prix.
Want a DD with some pep in it do a top swap. Cost around $800 or less if you know how to shop around.
Turbo if your going for all out power $1500+ occasionally you'll find a good used kit. Can cost upwards of $3k brand new.
Turbo = chances are you'll be spending another $2k+ on a built trans.
Topswap if your not constantly beating on it your tranny "should" last awhile. Some have went 150k+ on stockers. Other lucky to make it to 70k. Be prepared to swap a tranny in either situation though. It's a pull of the straw but if you take care of your car you minimize the chance of the parts wearing down faster.
At the end of a day it's a fwd Grand Prix. There's better platforms out there that have more potential! Decide when good enough is good enough and go from there.
