90k is nothing
No one is forcing you to race the car, but I wouldn't let that get in my way.
I'm not positive, but I'm quite sure you aren't going to get a 15x8 wheel to clear front LS1 brakes (even with grinding). Even if you did, you are giving up handling by going to a 15" wheel (larger sidewall, more flex), and if you want to go with the staggered look (taller tires in the back), I think that will mess up your ABS / traction control, as it will think your front tires are spinning faster than the rears.
Not trying to rain on your parade, just pointing some things out to you before you start spending money.
- Justin