You really need at least two of them, a small one for most stuff and a bigger one for axle nuts, cylinder head bolts, etc. Torque wrenches should typically only be used from about 20-90% of their range; below 20% they're inaccurate and near their upper limits there's the risk of damaging them.
In the US, the torque wrenches made by
Precision Instruments are quite nice, and can be bought from several online tool dealers. This is the company that supplies the wrenches for Snap-on (who then double the price).
