This isn't a perfect analogy, but here goes: you've got a confirmed date to the ball with the 2nd prettiest girl in town, but the 1st prettiest girl just broke up with her boyfriend and you think you have a chance. You could take the sure thing, or take your chances, possibly ending up with no date to the ball.
You're still waiting on OTS dates, and if you need SERE, you're probably looking at 2 years minimum in training with OTS->UPT->SERE->FTU and any other delays in the pipeline. A lot can change in 2 years. My gut says to take the sure thing, crush it, and someday down the road if you want to move and change units, that's not too hard of a stream to ford.
If you do want to pursue getting hired on another unit's board, transparency is your friend here. Like Brabus said, have a frank conversation with your SQ/CC and get his opinion.