Generally, I'm of the mind set that men already have equal choice. They likewise have the right to an abortion in the event of their own unwanted pregnancy.
However, I think a (imperfect) solution to this might be to allow men to sign a legal document upon learning of the pregnancy (like within the first 3 months) stating that they do not wish to be the father of the child.
If the woman carries the child to term, the man's name would not be listed on the birth certificate, he would have no legal rights to the child (ever), and would not be required to support the child in any way. The child would essentially not exist to him.
This would be a burden on the mother of the child, but a burden of her choosing. Perhaps some pro-life groups could come together to reward the choice of the woman in a situation like this and provide her with various forms of aid (parenting classes, monetary help, child care essential items, babysitting, etc.) if she needed it.