I have a Sealey one for lower torque ranges, and a Halfords jobbie from the late 90's for 20Nm up. Both have been good. The Sealey one is easy to take apart and service; the Halfords one would require drilling out a rivet.
I taught myself how to calibrate them after the Sealey one got dust in and stopped clicking - it's simple maths and there are plenty of decent videos on youtube. You'll not get it as good as a lab that certifies them, but you'll get it close enough it definitely won't round, snap or strip anything. I checked the Halfords one at the same time and was surprised that after 18 years or so it was within 10%!