Now this is the one part I hate about wrenching - feeling totally helpless about tiny details that I haven't stumbled across before.

I'm going to build a rear wheel. I've ordered a hub (Hope Pro 2), a rim (Mavic XC 717) and spokes (DT Comp 2.0/1.8 - according to Sheldon Brown aka 14/15 gauge). I want/need a new spoke wrench.

Park Tool sells FOUR: 80 gauge/3.23 mm, 105 gauge/3.96 mm, 80 gauge/3.3 mm and 80 gauge/3.45 mm.

Which one do I need?