You could also switch out Acrobat for Fist, make him a Martial Artist. It would sacrifice the 5' of speed BUT make a spear and polearm genius and he'll end up with a Reach of 4 at some point. A Giant fast moving spear wielding hit anyone on the battlefield menace who has a little bit of natural DR to his cause.
you know i go tot thinking about this build today, and if you did a giant 2 weapon fighter with throwing spear and martial artist you would have reach 7 at some point and reach 4 at first level.