I love mine for knocking off stuck wheels, impacting bolts and nuts by hitting the box end wrench with this thing, etc. Personally I'd add one of these as well: Vaughan RM24 14-Inch Professional Rubber Mallet with Flame-Treated Hickory Handle. I wouldn't worry too much about screwdrivers, just one of each is fine, or get a universal one with some bits of different sizes. I have 2 of these (one for the car and one for the garage) and they have taken alot of abuse so far.
Husky Metric Universal Wrench Set (10-Piece)-HSPW10PCMMN at The Home Depot On top of that you might want to add a spark plug socket (or equivalently a 5/8' deep), and I'd add one of these:
This is a good start and in a nice self contained case (though it has SAE stuff too which you don't need): Husky Mechanic Tool Set (92-Piece)-H92MTS at The Home Depot
You could get this stuff from Home Depot for pretty cheap.
