I hope you marked the orientation of the bearing caps and which side each was on before you took it apart.
You don't need a specialty 4x4 shop to have someone knowledgable in ring and pinion installations. Rear wheel drive vehicles have them too and there are lots of mechanics not working in 4WD shops that have differential experience.
Find a local 4WD club and see if someone who's a member has a recommendation. There's a Great Lakes 4x4 forum with lots of members in the Minnesota/Wisconsin area that you might find help in as well. http://www.greatlakes4x4.com/forumindex.php