I don't advise "reinventing the wheel" this way. By adding off-the-shelf 17" fronts, you are pushing the clearances to the absolute max, and will probably find many little problems with tire rubbing before the car actually rolls interference-free. Additionally, you'll probably find that the left side clearances are larger than the right- in fact, I've seen some undamaged Panteras in which the rt side wheel stuck out of the wheelwell 1/2" while the same wheel sat flush with the fender edge on the left. This is less of a problem in the rear, but some rear tire diameters are so short that your cruising speed is affected, your speedometer will be highly inaccurate and other little difficulties occur. And I'd also suggect factoring in a 10-quart oil pan as big fat tires allow such hard cornering, the oil sloshes away from the oil pump and you shell out your crank bearings rapidly. Strees-cracking of the body shell will occur as well, requiring stiffening systems, and you may find some new handling problems with ultra-wide front tires. Your normal Pantera parts vendors have alrerady thrashed this stuff out with their suppliers so the mentioned problems mostly don't occur. Unless you're experienced in this sort of stuff, be prepared for a real steep. potentially expensive learning-curve with some wheel-tire-brake rotor combinations Exclusiveness does have its price....
If you insist, to find what you need, measure your rear 8" Campy from the inner flange surface to the outside of the rim (called 'backspace') and do NOT exceed that dimension in any wheel front or rear, of any width or diameter.
