+1 for Lqd Torque/Carbogrip, or FiberGrip – all excellent.
Ritchey TorqueKey Great – only up to 5Nm so no chance of overtightening. Retails @ £12.99.
Or try Park tools torque wrenches – smaller one (part No TM1) goes up to 7Nm retailing at £50, larger one (part no TM2) goes up to 70Nm retailing at £60, neither need recalibrating.
Get in with your LBS and they may get them at a better price for you.