02 325xi - Performance/Necessary Upgrades

Hey i've tried posting this on here before an cant remember so much what feedback i got so im trying again.

The only catch this time is that im currently deployed so doing the research is difficult an i could use some help as well as advice from you guys who knw alot more bout this crap then me haha

I have an 02 325xi n have done the following so far

- Shark Injector
- Short ram intake
- replaced the stock exhaust pipe from just under the engine to out the back with 2.25in pipe n a RE Ikon Exhaust
- have aftermarket rims

i have the springs to lower the car n in addition to that im going to replace the shocks with Bilstein Sport shocks an those run bout 450 for the whole set, from wat ive found

some things that ive seen online are
-Rogue Engineering Power Pulleys
-Performance ignition coils (bavauto.com)

i cannot for the life of me find an affordable header, now after my deployment im having a kid literally 2-3 weeks when i get back so my hope for my bmw is to upgrade it performance wise as well as replace things that would help it to last well beyond the 120,000 miles it has on it now.

If anyone can let me know what additional changes would be the most beneficial as well as where exactly i can find the parts then i would appreciate the help