ARB makes a locker for the rear, model RD44. If you want a "lunch box" style locker, look at the thread stickied at the top of the Talk section:

http://www.4x4wire.com/forums/showf...mp;amp;sb=5&o=14&fpart=1

Its not a car; but yes those t-case gears fit. You need the ones for the slip-yolk case.

5.38 gears are readily available for the rear axle; much harder to come by for the front. 4.77 gears are available, but IMHO not worth to cost for swapping out over the stock 4.56's.

Tire size depends on how cut happy you are. Don't want to cut anything, 32's fit with no mods. 33x12.50's or 35's will require fender cutting.