VintageRacer wrote:

the best torque wrenches typically available, without going to really over-the-top stuff, are from here: http://www.torqwrench.com/

They make them for Snap-on, for example. My main wrench is a Snap-on Beam type click wrench, made by them. I also have one of these: http://www.srtorque.com/tabeam.html
that I got when an aircraft maintenance company was being liquidated. Harder to use, simpler, but more accurate and more expensive than the snap-on, when new.

I have other wrenches for engine assembly, that sort of thing. FWIW, a wrench that is accurate in the 400 - 600 lb range will cost in the $1000 and up range and will be about 6 feet long, 3/4" or 1" drive.

Brian