My estimates based on experienced amateur times, not professional shop times;
* Rear wheel bearings: cannot be repacked, so if you do anything with them, you replace them. I'd esimate 3 hours labor, plus the cost of the bearings, retainers, and seals, plus the time to press the old ones off and the new ones on the axle shafts.
* Diff leak? Hard to say, depends on where it's leaking. If from the pan gasket, maybe 1/2 hour. If from the pinion seal, an hour. If from the main seam where the two halves of the diff meet, don't bother, just get another diff or keep filling it up.
* Front stabilizer; I assume that means sway bar? I'd estimate 1 to 1.5 hours plus parts. More if difficult pressing is required for the rubber bushings; may another hour?
* Oil change, 1/2 hour.
* Wash engine? Do this yourself, or I'd guess they'll charge an hour.
Shops tend to have flat rates for normal items.