One thing I have learned on mechanical side of life is.... Anal retention can only help, and never hurts. Pull out the 1/4 drive 0-30lbs dial wrenches for yer plastics kinda anal.
As for the original question. Get what works for now. You can always upgrade later.
Torque wrenches need to be calibrated, and re-calibrated. I have yet had the need to recalibrate my snap-ons, but I don't use them much anymore, and they are properly used and stored EVERY time they come outta the case. Always set it back to 0!!!! I am sure the cheaper the wrench, the more prone it is to needing recalibration. Proper use is VERY important to torque wrench life.