Well, I sell the gear kits and install kits for the JK, but I couldn't recommend a shop. There is alot to the install, if you've got the dial gauges and calipers and such and can follow a manual very closely, you could tackle the job.
If you order any of these, make sure you add the install kit on each item as you add them to your cart, and type in this special coupon code at checkout
coupon code = shipmygearsfree (ships jk superior gears and install kits for free!)
dana 30 jk front 4.88
http://www.rjroffroad.com/superior-...-pinion-gears-offroad-c-562-p-1-pr-16920.html
dana 44 jk front 4.88
http://www.rjroffroad.com/superior-...-pinion-gears-offroad-c-562-p-1-pr-16920.html
dana 44 jk rear 4.88
http://www.rjroffroad.com/superior-...-pinion-gears-offroad-c-562-p-1-pr-16924.html