Looks like you shopped Amercian Muscle's site pretty heavily. They have a lot of cool stuff. Might also want to check out Brenspeed's site Mustang Performance Parts & Upgrades by Brenspeed
and Team Beefcake Racing Buy Mustang Performance Parts | FREE Shipping | Team Beefcake Racing
Both of the last two sell great mods for 1/4 mile racing. I like Brenspeed's service best. They have their own grind for camshaft - the Detroit Rockers. While I like Ford Racing, have to admit I think the Detroit Rockers are slightly better. Both they and Beefcake like the JLT cold air intake and that is what I went with - better price than Airaid, which helps fund other mods, plus Brenspeed's tune and CAI combo was a great combo for the $$$ and what it has done for my car.
From what I have heard, Hawk pads are the best. Would suggest those over Powerstop. FWIW.
BMR makes good products. I am leaning toward J&M and Steeda over those as they seem to be best for curves and still just as good on straight lines. But Rear Lower Control Arms and adjustable Panhard Bar would be money well spent. If you do springs, I would suggest Steeda or Vogtland.
Steeda underdrive pulleys are the best. You can get those on eBay from Steeda with paint scuffs for 179.95 and save a few coins. Steeda Mustang Underdrive Pulleys 2005 10 GT 701 0005A | eBay
Didn't see axleback exhaust on your list, might consider that along with the headers and midpipe.
Won't need subframe connectors unless you grow this thing to some serious horsepower.
Aluminum drive shaft is on my list too and my buddy added and loves the difference.
If you are planning to super or turbo charge, make that choice before you go too far and spend on things you will replace. Make a plan and stick to it.
Welcome to the S197 platform! Hope you enjoy your ride as much as many of us do.