Yeah, Racicot is not going to run for the House seat, period. In fact, if Rehberg vacates the seat to run for the Senate, we may have considerable difficulty holding the House seat because we have no one warming up in the bullpen. I heard some vague rumors about ex-Congressman Rick Hill making a comeback (he was forced into retirement when he was quickly facing the prospect of losing his eyesight), since apparently his health problems were corrected (I could be wrong, but that's what I heard).
The only other GOP statewide officeholder is the Secretary of State, Brad Johnson, and I don't know if he'd be anxious to jump into an open-seat House race.
Former Lt Gov Karl Ohs (the current state party chair) might also be a decent candidate.
I doubt that Secretary of State Brad Johnson would run for Congress if Rehberg runs for the Senate. He's only held his current office for a year, and won it by only 51% to 49%.
I think that state Public Service Commissioner Brad Molnar would be a good candidate.