Personally I wouldn't worry about using a lens hood on an ultra wide angle zoom lens like this. While they can prevent unwanted flare from light outside shot getting in, since you're at such a wide angle anyway the difference between unwanted light being in shot and out of shot is tiny. In the rare case where there is a flare source just out of shot, I use my hand as a temporary block.
If you really do want a hood, you do need to watch out for the coverage. Hoods designed for longer focal lengths will most likely cause hard vignetting.
_________________Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.