Who the Republicans finally nominate for POTUS isn't (or shouldn't be) an issue with anyone who wants Obama gone. It would be total foolishness and stupidity to vote for any third party candidate because there's something about the final candidate wot pisses you off . . A cold tuna sandwich would be a better President than Obama.
That said, IF, you really want to change your government for the better, get rid of any Federal Legislator (Congressman or Senator) who has been there for more than two terms . . He's not interested in your problems, he's busy getting rich. He's part of the problem . .
The Federal Congress and Senate will not pass a Term limits law, so we must do it for them. If he's an incumbent, go to your Party's Caucuses and put new blood into the system. And then do it every term until they learn that representing you is a privilege, not a guarantee that they'll have a lifetime job and get rich!