$10K can get you plenty! Anything over that I'd strongly consider a GT, but that's just me. We considered trading our 08 for a GT already, but didn't want the hassle of getting spanked on the trade and looing for a deal. Now I want to take the time and money and build a low profile sleeper. For $10K you should be able to whomp GT's, even some of the mdded GT's.
First thing I'd do is consider deciding on the power adder, the cornerstone, everything else falls into place after that. Are you trying to maintain a daily driver status or going balls out on the 1/4? For daily drivers I've read the X Charger fits the bill, for 1/4's go with the turbos, Powerhouse has a reat rep. Decide on this before the CAI/tuner so you're not spending money twice.
The rearend options will get you lots of different opinions. The 8.8 has more suface area, a bit more power handling. Some say they hit 500hp (using juice) on the 7.5, but I'm not sure that's safe or accurate, 300hp shouldn't be a problem. Didn't Ford start using the 8.8 once they were getting big power out of the 5.0s? Personally I like the 8.8 better. Whichever you decide, ditch the stock driveshaft for a one piece aluminum shaft from Shaftmasters, Spyder, etc. Those stocks shafts no likee going over 120mph.
Look into swapping the front rotors, caliper mounts for GT rotors and mounts. The calipers are the same.
Then you'll be needing suspension parts...springs, LCA's, UCA's adjustable panhard, etc..
It's easy spending someone elses money

Seriously, read up and read some more. Tackle some of the installs yourself to save a buck or two.