94 Cobra with 15X3 Welds Help!!!

How bad are they hitting the caliper? If it's "just a little", break out the die grinder and add a little clearance. (to the calipers) If it's a lot, then add enough spacers that "clearancing" the calipers and adding the spacer solve the problem. (That way you use the thinnest spacer possible.) The rule of thumb for wheel stud engagement is you'll need to have at least as much of the stud in the nut as the stud is wide. (You need 1/2" engagement on a 1/2" stud...minimum.)
 
The size of the spacer will depend upon how much you want to grind on the caliper. No grinding you will need about a 7/8" spacer if not an 1'', and you will definitely need longer studs. Order the studs from Maximum Motorsports get the ARP studs...do not get the cheap Moroso studs. It takes about 30mins to change out the studs very easy to do.

I have 15x3.5" Bogarts on my car, they have a 1" spacer but have a different offset to help tuck the wheels in. The welds are going to stick out quite a bit.

Orrrr....could change to a set of '99 brakes. and run a small spacer and stock studs.