Use the local guys! You've already established that they are capable and willing to do the job. You'll be able to get some really good advice about the muffler that will deliver the sound you want and the installation will fit your specific truck.
I've found that mail order exhaust systems, unless you buy the premium setups, lack in quality and fit, and wind up costing as much because of shipping charges. Another benefit of using a local shop is that you often get to watch a true artist at work. I trailer my vehicles 22 miles just to watch the lead bender use experience and his eyeballs to turn a piece of pipe into a custom piece of artwork in 30 minutes or less!!!!
Dave
