your goal is unattainable...that being 500+ hp without having a shitton of money to throw into it. You are going to need a built motor (pistons built around the turbo system, aggressive intake and exhaust porting, fortification in the rods, etc,,etc), significant computer modifications (something which noone has knowledge of for that type of HP) or a standalone, a custom turbo setup with a to4e+ turbo if you want efficiency, a transmission that wont break all the time, fuel delivery modifications... I used to build drag import cars, it piles up quickly. 400 HP is more realistic and even then with these cars you will probably have issues.

as a side note, aeromotive is the only fuel delivery system i would use but way high for only 500hp. I have used them on several high hp cars and they make a quality product.

Just as a guestimation, here is what i think you will spend at minimum

Built Engine: $3000
Fuel delivery system: $1000 (pump, lines, injectors, possibly a custom rail, pressure regulators)
Custom Turbo system: $4000 (a good turbo will cost you around a grand along, then you have to think about intercooler systems, piping, wastegates, blow off, custom intake)
Computer: $2000 I used motec/haltech/aem standalones, I have absolutely no idea how they would integrate with a car like this, between dyno and tuning time...rack up the $$$
Transmission: If you are using a TIP, there is going to need to be some programming, fortification in the torque converter and even then you will probably destroy them quarterly if not shorter.

Start your budget at $10 grand and factor in 20% for fuckups and specifics... Its not an easy task. It would be fucking awesome however.