The Goodyear GTII's have a reputation of being fairly hard and spin easily. Not much better than the Goodrich TA's.
Get a stickier tire and you'll have much less problem. As far as the rear, I've not heard much about problems with them, but if you plan to drag race or hammer it off the line a lot, you might want to consider upgrading the rear with a Torsen and some custom CV's rated at higher horsepower or going to a live axle arrangement.
www.dutchmanaxles offers some very tough axles.
Bob