"Also, the ol' Toyota calls for a 80W-90 gear oil in everything other than the engine (transmission, transfer case, front and rear differentials). I currently have Mobil 1 synthetic 75W-90 in there right now and am very pleased with it, but again, I'm not so impressed with Mobil 1 anymore, so any suggestions for other gear oils would be welcomed."
In general, Royal Purple gear oils seem to be well-respected in the automotive community in general. If you can get them, I would try them.
As for oil, anyhting will do the trick, I would do a quality conventional (Pennzoil, GTX, Valvoline) 10W-30 once a year. With the amount of mileage you are utting on, the oil will hold up just fine!