Welcome to LS1truck. If it were up to me (and I had $1000 to spend), then I would probably start out with all of the easy little mods (bolt ons) first:
CAI
E-fans
Headers
Pulleys
80mm TB
Tune
I would not do a cam or heads unless it is tuned. Throwing a heads/cam combo on there without a tune is not smart. Your tune needs to be correct with your mods so that you can get the mods to work as they were intended...
