I definitely would have though Gerlach would have been first given his support for LGBT Hate Crimes and voting against the constitutional amendment, but hopefully he does it sometime before he leaves office. Fitzpatrick should be soon to given he's got to survive a tough re-election fight this year. Justin Amash, Walter Jones, Jeff Denham, David Valadao, Chris Gibson, Bob Gibbs, Mario Diaz-Balart, Joe Heck, Greg Walden, Pat Meehan, Frank LoBiondo, Leonard Lance, and Rodney Frelinghuysen could be among the next potential House Republicans to come out in favor of marriage equality. Collins will almost certainly be the 4th Republican in the Senate to do so followed by Heller and Hatch and I could see Burr, Toomey or Ayotte supporting it down the road to.
To be honest, the fact that Susan Collins has been avoiding the issue - even if she has had ample opportunity and little risk of backlash; makes me think that she personally opposes marriage and isn't prepared to endorse. Maybe I'm wrong.
I think Flake will be the next in favour. Hatch will wait until his last term to endorse.
