Someone mention brakes, ahem!!
I have used different variations of Mustang brakes on race cars, so my assessment is more function than form, but I'll put in my 0.02 anyway. Note, this is a 260hp race car that sees max speeds of about 130mph on most tracks, track sessions are 20-45 minutes long. Brakes are critical in this environment.
I'll stick to sn related setups. This applies to 100% working systems, bled with fresh fluid. Pads make a big difference how brakes feel in initial bite, sustained braking at high temp levels, and dreaded fade. Some of my experiences may not be apples to apples because I've used several different pad setups including HAW, EBC, Carbotech. Currently I use HAWK DTC70 in the front and DTC60 in the rear.
Stock 94 GT brakes
Street:
Absolutely fine. There is just not enough abuse you could do going to 7-11.
Track:
Fade comes in about the 3rd lap of hard driving, then you're forced to drive a little easier until brakes come back.
Feel:
Blah. Pedal down, car stops.
Upgrade to 99-04 PBR twin piston GT front caliper
Street:
Improved over the above setup. Brakes feel more responsive, not as much pedal effort needed for hard stops.
Track:
Fade comes in after about 10 minutes. However, with brake coolers the fade is reduced, practically eliminated.
Feel:
More responsive than stock by leaps and bounds. System is very well balanced with 1 step less aggressive pads in the rear.
Upgrade to 13" front rotor Wilwood 4 pot, stock Cobra rear.
Street:
Too much, but definitely usable.
Track:
Very well balanced, brakes are there. Period. You can absolutely be 100% confident this will launch you through the windshield if needbe. Brake coolers are a MUST on track.
Feel:
Wow.
My original plan for the 13" setup was Cobra calipers. But decided on the Wilwood for 2 reasons. Pad cost and longevity, when you're paying $220 for a set of front pads every 2 weekends of driving versus $180 that lasts almost a full season is significant. I also had a chance for the 00R Brembo setup, decided with Wilwoods because I can buy a caliper for $150 from anywhere online. If the Brembo caliper got trashed I'd have to buy a pair.
For the street, I would have no issues going with the 00R Brembo setup. It would likely be a 1 time purchase, HAWK HPS or HPS-Plus pads and you're ready for anything the road has to throw your way. However, for the track I would still do some coolers. Just for track use tho. May not be necessary until you get some experience and start going 'fast', but you don't want to ever step on the brakes at triple digit speed to find they are not there. When fade hits, it's hardly gradual brakes feel fine the turn before, the next turn your pedal is rock solid and she ain't slowin' down.