I think its a job you could do yourself. It is a messy one, but you can do it yourself. It just means you'll need to buy a few tools.
I was at harbor freight yesterday and noticed they have pin spanners ($5) dial indicators and magnetic bases (about $20 for the set), feeler guages and most of the other tools you need to rebuild these rear ends.
Speedway motors also has a rear end rebuild tool kit.
As far as the install kit goes- It is definately a good idea to replace the bearings etc... I would check with some of the standard parts houses, especially NAPA, to see if the price they can sell you the individual parts compares to Patrick's. Having a list of the parts you need is very helpful. In the more modern 10/12 bolts there are two axel seals, a housing seal, a cover gasket, three bearings, a crush sleeve and a shim kit. Maybe someone can chime in with the parts for this project...
