There's lots of options for you. It all depends on how much you value your warranty. If you're not worried about a warranty then you can do any tuner you want. Some are better than others. The biggest thing that will help you is to get rid of the DPF in the exhaust. A performance exhaust system will help you a lot. And you'll need a tuner to make the truck run right after you remove the DPF. So we sell package deals with a tuner and exhaust, since they pretty much have to be sold as a pair to delete the DPF.
As for installing things, it's pretty straight forward. Just simple hand tools will do it all. You shouldn't have any problems doing it yourself. And if you buy from the right person, many of us vendors on this site will be just a phone call away if you have any questions.
Let me now if I can help you out. We carry a big variety of tuners, intakes and exhausts to suit your needs. I can make some recommendations based on your wants, and your budget
-Jesse
Husker Diesel