AF does guarantee jobs but only from a list that you make. You make a list of 9 jobs and an aptitude area typically and when jobs drop whatever is highest on your list from that drop you can get a contract for. You can technically deny a job that they offer you from your list but your recruiter may not be happy about that, they can kick you out of DEP for doing that enough times.

Go talk to a recruiter and explain to them that you want that job, some may be flexible and let you wait for that specific job. In my experience I was offered a job from my list I wasn't too keen on and spoke to my recruiter about it, he was willing to work with me and wait for one of my top picks.