what Wheel Width & backspacing recommended
 

For 26x10-15? looking for advice for a 1994 Camaro
Bias Drag slicks -wanting to use Weld PRO-STARS
which Brand works better? Hoosier or M/T

To run a 15" wheel you will need to grind/shave the brake calipers down to get them on.
And also will have to get longer wheel studs.

you'll want a 15x10 wheel to keep the tire square, to accomplish this, you'll need something with a 7.5 BS

also be prepared to cut the bump stops and as was previously said, grind a bit of the caliper down