For headers check out pace setter or hooker. As far as tires i have had good luck with the nitto 555.

 

I'd get some pacesetter long tubes. I've always been a fan of them. And all lids are pretty much the same, I'd just get which ever one looks the best. Then I'd look into ud pulleys (many mixed opinions about them), ported and polished throttle body, ls6 intake and a tune.

 

tires and a small hit of gas.