Snap-On is the best, and priced accordingly.
www.snap-on.com
Proto is the best balance between price and quality. Available everywhere, but the cheapest seems to be
www.jlindustrial.com Once you get to J&L's site use their search engine to find torque wrenches.
Sears brings up the rear with being easy to find and cheap to buy.
Do not be afraid to pay the bucks for a good torque wrench, it will last the rest of your life and the better ones can be re-calibrated 10-20 years down the road for a very reasonable fee. And torque wrenches are also very useful to do automotive repairs, saving money to buy more tools

As far as types, you'll need at least two. One "big" one, 1/2" drive, that will go from 30 foot-lbs to over 200 foot-lbs for things like axle bolts and such, and a "little" one that will handle say 25-250 inch-lbs. Notice the difference in units. Inch pounds are way smaller than foot-lbs, so the "little" wrench will typically be either 1/4" or 3/8" drive.
One note about the quality of the wrench, pay attention to where it's made. If it's USA, Japan, or Europe it's a good one. Taiwan or
shudder China, it will make a nice paperweight, nothing else. NOTHING ruins the day like a snapped off bolt you were tightening verrry carefully.