13 inch rotors

I think someone somewhere has a braket kit where it moves it to use 13 inch brakes. if you buy a set of cobra calipers (and most are like thing) the bracket is made into it. I order a front kit front stangsuspension.com and it came with brembo cross drilled/ slotted rotors with the cadnium plating (I think that was it), cobra calipers (which have pads already in them), and maximum SS lines. with tax and shipping it was like 500 I think. I paid top dollar for it but I'm over all pleased with it. I know you can find it cheaper out somewhere but the guy I delt with was real cool. only prblem I had was getting my rotors in. some backorder issue with them.
 
Were would you go to just get the bracket??

I have some 99+ calipers and I know they will just bolt up fine (with alittle grinding) to my stock spindle. However, I have been kicking around getting the 13in rotors and using the 99+ calipers with them.

My thinking is this.

the 99 caliper has larger twin pistons over the the cobra ones. The reason the cobra kit is better is the larger rotor that gives better mech. advantage...so the same bigger rotor and a caliper with a larger set of pistons "should" work better correct?