They could vote with the existing Boener plan without making the decision to raise taxes on a single person.

Because the decision was made when the temporary tax cuts were implented; it was always scheduled that they would revert to their previous rates; that reversion has just been postponed a few times.

So I would argue that they technically don't have to vote for a tax increase on anyone.

All the Republicans have to do is decide who they're going to extend tax relief for whomever they decide to do it for, and let they already existing laws go into implementation for the rest.