Finally I have some results! I've been on the phone with several people today and I've come to the final conclusion on what I'll be doing for rims and tires for the Mustang.

Rear wheels
Centerline 045907545
Wheel Size: 15" X 9" Rims
Rear (backspace) wheel clearance: 14" at hub to 15" at bead
BHP 5 X 4.5
Back spacing 6.5"
Off set + 39 MM
Cost: $199.95 per wheel

Rear tires
Cooper radial GT
Size 295/50 R15 white letter
Overall height: 26.8"
Difference .20 Less then stock 27"
Cost $117.95 per tire

Total rear cost:$635.80



Front Wheels
Centerline 045755545
Wheel Size 15" X 7.5"
Rear (backspace) wheel clearance 14" at hub to 15" at bead
BHP 5 X 4.5"
Back spacing 5"
Off set +27MM
Cost $195.95 per wheel

Front Tires
Cooper Radial GT
Size 215/60 R15
Overall height: 25.16"
Difference 1.84" less then stock
Cost: 89.95 per tire

Total front cost: $571.80

Total wheel and tire upgrade cost W/O shipping: $1207.60

The front caliper clearance is going to be super tight but from my measurements it should work for me. The back spacing tapers from 15" to 14" from bead to surface mount. The caliper also tapers but it tapers in the right direction so I should be good to go. If there is an issue the tech rep at centerline said I could use a small wheel spacer to gain enough clearance.

My local pep boys sells Cooper so I'm going to wait until they have a buy 3 get one free deal to save on the tires. I should also be able to get the rims locally to so I can avoid the added costs of shipping.