Don't waste any actual money on stock shortblock. Just go aftermarket and be done with it. I went through what you are doing a bunch with a turbo setup. Finally went aftermarket never looked back. Good luck
Stock rear springs. Coil overs in front 14-150. Tubular double adjustable upper and lowers. You dont need the quad shocks. Solid bushings. Pinion angle at -1.5- -2. Single adjustable shocks.
EBay corral or Craigslist is your best bet. I've seen some real nice interior stuff on the corral in the past. Problem is it's all getting much harder to find
Who cares, it's just a car. Don't let other peoples ignorance get you worked up. Id say about 80% of mustang owners are morons, actually a lot of car enthusiasts are morons come to think of it. Not picking on anyone here, but its pretty much a fact.