A crankset is consist of two thing mainly, a chainring and two cranks and bolts that hold the chainring on the one of the cranks.

That Tec9 looks really good just for a starter fixie, get it if you want to...barely 50 bucks + shipping, good deal 160mm is kind of short though, get the 165mm.

However, I'm not sure what bottom bracket length you'll need but a 103 bottom bracket would give you a straight chainline.