It is a good idea to use the recommended anti-seize compound (or similar) on the bolts (between the head and the rotating spacer) to ensure that you are getting a true torque reading. If the head binds to the spacer prematurely you could be getting a "click" before you are at the desired torque.
As for torque wrenches, here is what I use:
SK Hand Tool (SK 74151) 1/2" Drive, MicrometerTorque Wrench with Case<br><img src="/free-shipping.gif" width="79" height="26" border="0"> - SK 74151
Also, tooltopia.com is a great place to by tools. Good prices and fast delivery.
Cheers,