Decent handling susp setup?

Sorry If I come off as dense, Im just trying to make sure I'm on the same page, you are giving me a ton of great information.

Hypothetically, If I'm considering 255/45r17 on all four corners using those 17" Cragars that are 9 inches wide. They have 5 inches of backspacing. With only 5 inches of backspacing I probably won't have any clearance issues with tie rods ends that others have had since they had more backspacing. Of course If I were to go that route I should order one of the wheels to do a test fit before ordering the rest of the wheels and new tires because like you said it comes down to rim design and the design of the rim may or may not interfere with the tie rod ends. Also to check to make sure the rim will fit over the large disc brake center. Am I following you correctly?

here is a direct link to the 9 inch wide wheel they offer.
https://www.summitracing.com/parts/crr-3428912/overview/

With a set of 17x9's you'd need a minimum of 5.6" of backspace to keep a set of 255/45/17's off the fender. Minimum. Any less than that and it would interfere on the fender side.

Surprized more folks aren't looking into other alternatives besides mustang wheels. Don't the crown Vic cop car wheels have the same bolt pattern in 16"? How about the early Toyota pre-runner (the blue ones with body kit) wheels. They're 5 on 4.5" too and look pretty good. Some of the newer jeep wheels look ok too.
The center register size in the front is easy to fix by having your machinist cut the hub snout down to fit the wheel.

Tire selection for 16" rims is even more abysmal than 15" for sizes you'd want to run on one of these cars. And they have pretty much all the same backspace limitations as 15's, meaning, you can't get enough backspace to run a decent width tire up front before you start hitting suspension parts with the rim.