I'm sure some if not at least half of them do. Would the 3rd party want to run for all 435 seats, risking that some anti-Obamacare voters lose to the Dem due to vote splitting? If there is enough money to fund a 3rd party, it doesn't seem like it would cost as much to just target the bad Republicans in primaries. And if you can't defeat the Republican in a primary, how could you defeat both him and a Dem in the general? And if the Republican party doesn't give your candidate enough funds in the general, just send him from money from the outside Tea Party coalition. The idea that a 3rd party gets formed and sweeps the next election seems more far-fetched than successfully repeating the formula of primarying out RINOs that's had some success so far, including Cruz's election.
At least half the independents, and maybe as much as 1/3 of the Democrats, loathe the GOP and would never vote for a "Republican". Where I live, the GOP is about country clubs and looking down on guys who get their hands dirty. The new party has to lose the clubbers. There are a lot of voters to gain.