4.6is
Front Rotors: 356mm
Back Rotors: 324mm

3.0/4/4
Front Rotors: 332mm
Back Rotors: 324mm

Both sets of rotors are wider for the 4.6is due to the venting and have a wider caliper to accomodate them.

I think you will find the aftermarket brakes are quite expensive and offer minimal performance characterisitc upgrades over the 4.6is brakes. Especially when you consider the $2,500 - $6,000 price tag for the alternatives.

If you want to really have these brakes look sharp I can have them powder coated the color of your choice and rebuilt for an additional cost.