I also had leaky axle seals which the shop fixed too. I think I got a fair deal. Cost was $3250 to regear, new axle seals, and to put in the Eaton E-Locker. I live in the Phoenix area and I did call around for pricing before having the work done. I also wanted a shop that specializing in this work.
I have no plans to run larger tires. I drive on the highway and it speeds of 75mph. I thought the 4.10 gearing would be pretty good for that, 2500rpm at 75mph in 5th gear. I could have gone to 4.56 but decided against it. If it turns out I'm not happy with the 4.10 gearing I'll go to 4.56.
So far I'm really liking my decision. The TJ certaining has more pep now.