It is very difficult to find someone who knows gear setups and how to do them properly.
Setting the pinion depth,gear backlash and side bearing tension are very critical. All will contribute to good performance and a long lasting quality job.
The Auburn gear sets are good quality,along with Richmond Gear. Make sure that the axle is completely washed out and cleaned, seeing that you have found metal in the gear lube. This also requires the replacement of the axle
bearings. Do the whole thing while it's apart.
If you are keeping the truck, think about investing in a PML finned rear cover. This adds extra cooling and capacity to the rear axle. A big plus on the 9.25 rear.
I will say this. Having the dealer do it, may be your best bet. They have the proper factory tools and training to do it right. And standing behind the work is very important. You may pay a bit more, but unless a mechanic REALLY knows how to set the gears up, it could be an ugly expirence. The next best would be a specialty truck shop.
My last Ram was a test bed for modifications. A 2005 5.7 Hemi Quad Cab Off Road 4x4.
7 years of NHRA/IHRA drag racing all on the original factory 3.92 gears. I won't bore you with a list of what was done to it, but a 5600 lb 4x4 that ran
a best 0f 12.84@106 on DOT drag radials is no slouch.