Honestly, I wouldn't waste my money, buy some other cool tool that you will use more frequently. I have one, got it from Fasst, probably hasn't been out of the toolbox in a couple of years. get a good set, emphasis on good, of spoke wrenches, I had a pro circuit wrench with replaceable tips, unfortunately it got stolen, I next purchased a set of the motion pro wrenchs and recently bought a set of the ergonomic spoke wrenches.
A spoke torque wrench may be cool, and I think they work fine on new spokes that have been anti seized, but if you try them on a set that have been in the bike for some time, you don't know if they are seized or torqued. I like to go by feel.
How have you been tightening your spoke? has that been working for you? if so I you make my point.
