Have to agree with tsxslow6 on this one. If you want to start modding your gp whether it be with an m90 or a turbo, bottom line is you need some money set aside. How are you going to go about tuning? If you don't know anybody who can hook you up, you'll need to buy a tuner and pay someone to tune it. Or you can learn to do that yourself, but since you're here asking these types of questions, I doubt you could handle that. How much power do you want to make? I'm assuming when you fork out at least $800 + money for tuning you will be very tempting to go wot more than a few times. I'd have money aside for a built trans. So that will be $2k+. We need to know the op's goals before we can make the best suggestion. If he just wants and extra 40-50whp then I'd recommend a topswap. But if he wants to get 280+whp numbers, turbo is what I'd recommend.