dont get the mzr internals...they aren't any better than the ones you have. go forged.
the disi head is great but you'll be hard pressed to get the tuning right. that's what is holding back the ms6 guys and soon the ms3 people will realize that too.
stick with the mtx75. parts are cheaper. the lsd in the ms3 has yet been proven reliable. it's made by the same company who made the msp lsd's and they are notorious for going out.
i wouldn't look to the ms3 for ANY parts. the aftermarket is much better and much cheaper.
never understand why ppl want to replace oem parts with more oem parts.