Well, here's the thing: I'm guessing you are on the original motor, probably higher mileage, and you're wanting to get new 5.0L V8 power out of it. 

Depending on mileage, you may want to rebuild your motor to handle the extra power. Realize that the old school 4.6L GT's were putting out 2xx horsepower or so, not exactly Earth shattering. However, they were very reliable motors and you will be sacrificing reliability for more power.

I'll try to keep this as simple as possible. There is more to a supercharger than just bolting it on. You also have to consider: the transmission's limits, getting it tuned (you MUST get it tuned), what fuel you want to run, what gears to put out back, what tires you want to run, what size fuel injectors to run, what temperature spark plugs you need, so on and so forth. I get cars in all the time, typically Mustangs and Camaros, that guys have spent a week putting a supercharger on and now it is running terrible and they can't figure it out. Well, you are adding a whole lot of induction and you left all the stock internals, fuel injectors, and tune in place. Of course it runs bad because the ECM is freaking out because it has no idea what is going on.

For your application, setting aside motor concerns, I would recommend a ProCharger. They are a cheaper kit and give a lot of bang for the buck. They also have a pronounced whine on the Mustangs that sounds great even at idle. That being said, is it going to be a race car or a show car, or both? There are polished kits and unpolished, so you need to decide if the extra shine is worth the $2000 to you. 

Speaking of money, supercharging the car is something I would have a professional do. Yes, I understand the desire to work on your own car and I applaud that. But this isn't a bolt on or a simple cut and weld process. You'll need to be running belts, installing pulleys, and dialing in a tune. And you want a dyno tune, not an email or pre-canned SCT clunker tune. Put it on a dyno and get it running stoich, because if you don't you'll wind up having the "ProCharger Pop" happen and blow your motor. A good, reputable shop with a well-known tuner is what you need to look for. Ask around the Mustang forums and find out what is available in your area. Look specifically for speed shops, not the local mechanic on this one. I heavily support local and independent mechanics and have zero doubt they could install it....but they aren't equipped with a dyno and the specialty knowledge required to get the most performance, safely, out of the car. It isn't what they do every day, and that's what you want.

That said, specialty skill comes at a cost. Not sure what you have for a budget, but realize you are $6k in just the blower parts (an example can be found here:  https://treperformance.com/i-157540-ford-mustang-gt-4-6l-2v-1996-1998-procharger-stage-ii-intercooled-system-with-p1sc.html?network=g&device=m&keyword=&campaign=1413523126&adgroup=pla-298365603781&gclid=EAIaIQobChMI9qLU4P-J8gIVG21vBB0cgwA9EAQYCCABEgJYEfD_BwE), another $2k in labor to install it, $800 or so for a tune, and that doesn't count the other parts needed to really make it work. A quality supercharging job, on a stock vehicle, can easily go $10k - $15k. That's all the extras, installed, tuned, and ready to drive reliably down the road on a 93 Octane tune. It will definitely cost more than the car is worth, many times over. So just go into it being realistic on that front.

Too long; didn't read = Have it done professionally by a good shop and expect $10k - $15k in expenses.

Don't do it.

My Gal Pal had a 2001 Mustang GT with the 5.0 engine, { aka, the 302} and it put out 435 HP.

You need more than that?