Dupont Teflon dry-film or SuperLube PTFE/Teflon dry film for exposed joints:
http://www2.dupont.com/Consumer_Lubr...s/dryfilm.html
http://www.jamestowndistributors.com...?pid=4008&BASE
Pretty much any automotive chassis grease will do for the ring gears. I use Mobil1 just because it's what I keep on hand for automotive use anyway; but again, any will do.