My fronts are 15x8 +36 949Racing 6UL wheels (11.6lbs! see link), which are mounted up on custom 8mm spacers. The front of my car has Sector111 V2 steering arms and -2.5deg camber. With 205/50/15 RE71R there is a ton of room left, at least static. You should be good with the hoosier in that size.Spacers should be fine when used correctly. Like someone else said, swap to forged studs and get the spacers custom machined to be hubcentric and wheel centric. I just did this and fit 15x8 and 17x9 wheels with 205 and 245 RE71R tires.
I am in the process of buying a third set of wheels for track use and am going 15's all around (currently have 17/16 & 16/15 wheels). Looking at doing a 15x8 with +25 offset on all fours with a 205/50 Front and 225/45 rear A7 tire. I have confirmed the rear is fine with a buddies wheel but could not do the front. Can you tell me what offset you run on your 15x8 front and if you use any spacers and what camber you run?