Gear oils I was able to find, but have not used yet. Our club is trying to locate currently.

Quaker State GL-4 75W-90

and

Noco Gear Oil GLX 75w-90 GL-4

Also from Voy (I'm assuming this is KaybeeJay's post there)

75W85 fluid by Castrol called Syntorq.

This link confirms it's only available in 16 or 55 gallon drums. (Good to be part of a 4x4 club if this is the only quantity you can buy.) :)
http://www.silcodistributing.com/castrol_products.asp

and then there is what xterraparts.com is selling: Royal Purple
http://www.xterraparts.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=Xterra&Product_Code=RP-75W90&Category_Code=

Our club ended up buying a 16 gallon drum from the dealership. Supposedly the Quaker State is available in smaller quantities but GI Joes didn't come through, so we decided to just make a group buy. One of the advantages of being in an Xterra club. :)

My Tracker needs 75w85 for the tranfer case. I also couldn't find it at any parts store. The owners manuals however gives a GM parts # for this lube. It can be purchased at your local Chevy/GM car dealer's parts room. The bottle/can only says Manual Transmission Lube but I assume it is 75w85. The GM parts # is 12346190. $20 per quart synthetic.