USAF Job with Reserves?

I want a boom operator job at the base near my house. Since I'm going with reserves, I should get that base right? FYI, they do have the KC-135's there. How do I get a guaranteed job? I told my recruiter that I wanted that job and I have the asvab score for it. He said I would need to get interviewed for it as well. I go to meps next monday, 20th. How soon after should I know if I get the job? Thanks!