There are a couple of "problems" with the SVO or Mark VII brakes. One is if they have stock brackets, then the axles are 1.25" longer than Fox cars and they push the wheels out to the very edge of the fender. 17x8 will fit, but just barely. You would most likely have to roll the fenders and you will still have some rubbing of the tires. Second, they have a really large caliper (54MM?) and unless you match them with the 73MM front brakes, you will have to cut the rear pressure to the least possible with an adjustable proportioning valve or possibly experience lockup and have the rear swing around in the wet. I know from personal experience on this. Another drawback is they are not painted or aluminum calipers, and will rust up or look "bad" if not painted or at least clear coated (what I did on mine after sandblasting).
The pros - they are vented rotors and are just a tad bit smaller than Cobra rear brakes and better than the 10" solid rotors in the base and GT models. You can modify the brackets to use Fox length Ranger axles and keep the wheels under the fenders, a requirement for 17x9" Ford wheels. See:
http://home.pacbell.net/black306/tech/reardisc.html . Plus you already have them, saving you some $$ buying Mustang brakes.