Here is my advice to you.
Find you a cobra crank, some H beam rods, and get you some 9:7 diamond piston's. 9:7 is the perfect compression for what you are wanting. Once you have the parts, Call up John at Modular Performance. He was on the design team for ford when the modular was being designed. Have him assemble your short block. He is by far the best modular engine builder. As for heads and cams, Call up Nick at Modular Head Shop and get a set of his stage 2 heads and stage 2.5 turbo cams. Whatever turbo kit you decide to go with, get a forward facing kit. They spool a lot faster and make more power on less boost. Also, a 70-76mm is all you will need. As for a fuel system, go with what you picked out. For a clutch and transmission, I would call up Promotion. IMO, they have the best transmission's for the $, and their clutches are the best in the industy IMO.
At 20psi, that combo above made 672rwhp and 720rwtq with a snow 675 meth injection through a 5 speed WITH THE STOCK PLASTIC INTAKE ON PUMP GAS. With a nicer turbo such as a bullseye S374, and an edelbrock intake, you will make over 700rwhp easily. Probably closer to the 750rwhp range. Once he swapped over to an auto, the car ran 10.14 at 139mph at full weigh (3600lbs).
It's a simply, tried and proven combo.
If you dont belive me, or have doubts in my info, feel free to read about it:
Dyno results today... - Ford Mustang Forums : Corral.net Mustang Forum
Also, This is my last bit of advice. I saw where you were asking about saving some money on some stuff. There is nothing wrong with that, but dont sacrafice quality for money savings. Also, here is a little saying to remember when building a car, it's honestly true about 100% of the time:
If it's Fast and Cheap, it isnt reliable
If it's Cheap and Reliable, it isnt fast
If it Fast and reliable, it isnt cheap
Not trying to scare you away. I honestly hope you follow through with it. Good luck on the car and keep up updated.