Give DP-Tuner or Tony Wildman a good look for your tuning. You won't go wrong with either.
The thing to understand about diesels, the more fuel you can give it, the more power you make. When you make power, you make heat, and lots of it.
Before starting any mods, get some gauges, EGT, Boost and tranny temp. If you start modding without the ability to watch things like Exhaust Gas Temperatures, you may melt a piston if you can't monitor how hot things are getting. A up-graded exhaust system is another pretty much mandatory item before doing things like chips/tuners or turbos. If you go too big too soon on a chip or tuner without upgrading other the components of your engine, YOU WILL BE SORRY!! Instead of spending $$$ on upgrades, YOU WILL be spending $$$ on repairs that you could have spent on upgrades.
It's a viscious cycle refered to sometimes as PMS (Powerstroke Modification Syndrome).