Where should I begin with my 4.8??

[kerrige]

For the money your going to spend on the 4.8 you could easily buy a 6.0 and be way ahead.

Agreed a 6.0 swap is your best bet in California. You will spend right around 2k, but you will net 80rwhp. Here is some quick math.
Headers $500
High flow cats $500
Catback $400
Tune $300
Intake $250 you will need a Cali legal intake the $50 ones aren't legal.
All that will net maybe 45rwhp.
Basically you will spend 2k in a hurry for Cali legal mods and get way less power.