5.3L performance

I am trying to find a way to boost the performance in my 2006 GMC Sierra Crew Cab 5.3L. I have already installed an AEM BruteForce Intake system and have put smaller pulleys on both the alternator and waterpump. Beside spending 4 to 6 grand on a supercharger system( believe me, I really want one), what other mods can I do without breakin' the bank? This is my first step into the computerized fuel injection motors, I am used to a small-block 350ci with carb. If anyone out there can just point me in the right direction it would be great.  

you've got a lot of options to pump up your ls1 engine. the aftermarket companies' build everything from more aggressive cams to higher flowing cylinder heads, better intake manifolds etc. Of course, getting past a smog inspection is always an issue though.

we just added about 50 peak hp to an ls1 with a Comp Cams Thumper series camshaft and new valvesprings.  

Well, emissions testing is non-existant in Florida, so I am in the clear. I have read up about a couple of these mods and a lot of them do not work with the L59 engine. I have Flex-Fuel and I have read that the computer has to be adjusted in order to work with a different cam and/or heads. I have priced certain programmers, and in order to make these mods, the programmers run anywhere from $800 to $1500. The Ls1 is a completely different animal seeing as it is a standard 5.7L 350 motor with full electronics. Yet based on the same design, the mods are not the same and most will not fit this application. I have dyno-tested the truck at about 285 at the rear before the intake kit and pulley conversion. After these it was at just about 320 give or take. But I am still only running in the mid to high 15s in the 1/4 mile.  

We do not have any emissions testing in Iowa either. I've heard that Thumper cam in a 5.3 and it's got a nice lope. So just the camshaft and valve springs got 50hp, nothing else done? That is awesome!

Can you list part numbers and prices for those items Mike?