Overall with 93 octane tune, you're looking at maybe a 20-25 HP increase the flywheel. You're looking at around $1200-$1500 in parts and another $1000 to install if you're not doing it yourself (most of this is header installation). You'll also need a custom dyno tune if you're getting a new MAF meter. Figure in another $250 for that. I've noticed you didn't include the best bang for the buck mod there is; gears.
You're looking around around $2500 if you have all the work done professionally. Frankly for that kind of money a GT looks like a much better deal.
With any intake your only looking at a max of 7 hp. The headers might give you a 15 hp gain whereas the exhaust will maybe only give you a max of a 5 hp gain.
The throttle body and the airflow meters should give you about a 50+ hp gain. So in total I would expect a 60-70 hp increase at the flywheel.
The header like 5hp cai 5hp exhaust maybe 10-15hp and don't waste your money on rhe throttle body or the mass airflow meter unless you are going with turbo/supercharger. Instead of those look into getting a tuner. A handheld tuner is good like $300 and will add more hp the more mods you do but by itself it will add like 10-15hp if used with 93 octane.