There's no way that 17x9 +38 is fitting up front as is.
First off, you'll be rubbing the strut housing on the inside, and 2nd you'll be out past the fender. You'l need a spacer to get it away from the strut, then you'll be even further out past the fender. Some serious modification will be needed here.
The rear 17x9 +38 will be damn near perfect. I think a 9 inch rim with a 35 offset sits perfectly flush with the rear fender. Don't forget, you're gonna have to roll the rear fender to fit these without rubbing, but it'll look damn good.
All in all, I have to recommend against this. The rear is perfect, but the front won't fit. And if you modify it to fit, it's gonna look way strange with a flared front and straight rear. Plus, the car will handle like poo poo. The MR2 is designed for a staggered set-up. Meaning wider in the rear, not the front.
If I were you, I'd try to see if somebody else has a set of 17x8's. This way, you can swap 2 and you both have a staggered set-up that'll actually fit.
Just my 2 cents.