Black Bear Performance, no questions asked. Dont buy any of those hand-held programmers like Superchips. They don't give the results like a professional tune will. With a Black Bear tune, you can tell them exactly what you want. They can cater a tune to whatever octane you wish to run. I chose 93oct and it was worth the extra few bucks at the pump.
A tune alone from these guys should help you alot. But if you already have a couple bolt-ons like intake/exhaust, then that will give them more room to work with. I recommend that you buy a good intake along with a good catback exhaust, and then go get a tune. Those three things should really wake up the truck. A couple good brands for intakes are K&N, AEM, and Volant. For exhaust I'd say Magnaflow, Corsa and Borla. I'm running a Flowmaster but I'd stay away from that. The others will give you more power.