Some people like the PS headers, we have installed them, they do the job, just dont hold up real well it seems. Check out Melrose stuff, KOOKs or American racing, those are my favorites, fitment and horsepower gains.
As far as the cam goes, springs and pushrods are a cheap insurance for him, I have many styles in stock for the LS1, PAC, COMP, AFR. I like a lot of the Texas speed grinds, or the thunder racing grinds. I would suggest this if you want an off the shelf
Thunder Racing Custom Camshaft
"TR 220-112" - 220/220 .551/.551 112 LSA 1500-6500 RPM Power Band. Computer Tuning Required with automatic transmission cars. A very well balanced camshaft that makes excellent power across the entire RPM range. Due to the fast ramp rate of this camshaft, the use of 1.8 rockers is not recommended.
Then get comp 918's with 7.4 comp pushrods. Then get a tune!