Just a note that it may be tough to find a single size wrench that will do all the jobs you might encounter. I have three torque wrenches, not because I like them, (although I do confess they are one of the tools that make me feel professional when I use them. Those and the impact driver**) but true confessions aside, there are a wide variety of applications.
For wheel lugs and also things like the front axle nuts on my 4MATIC, you need a fairly hefty bugger. Mine is a PROTO 1/2" drive. I think it goes up to 250 or 30 ft-lbs. The second is a Snap-on 3/8" drive, which I bought when I was pro, and that stops around 80 ft-lbs. or so. It is just the ticket for most engine assembly type of applications. And the last is a True-Craft or something, which reads out in inch-pounds. That one I don't use much, but if you're going to do something like adjust automatic transmission bands, you'll need one of these more delicate sizes. I also come across the occasional small guage fastener that requires something of a precise torque.
In general these wrenches are more accurate toward the middle of their ranges, so one that just covers your desired torque, especially at the low end, is probably not a best choice.