Active Duty or Reserves or Active Reserves?

I have a bit of a complicated question. I am shipping out to BMT/AIT in 14 days. I desire to be as active duty as possible, but decided on reserves due to the MOS and squadron (AES). I was told that there would be opportunities to be essentially an "Active Duty Reserve" after AIT, as I am completing my CEC's and waiting for my other special schools (SERE, Water Survival, etc..).A new Airman returned to our squadron stating that he was not on active duty orders due to budget constraints. He is working on his CECs, but essentially on his own time. Our other 4 newer A1Cs were able to be on Active Duty Orders while they completed CECs. So, is it up to the budget? Or is it more an issue of who wants temporary assignments or more active orders? If the budget rules all why would my Commander say I would be able to be on Orders indefinitely? I have passed up civilian career (consulting) opportunities to pursue AES and eventually an advanced medical career in the USAF. Am I better taking my chances with Active Duty, even though I gamble with no guarantee of landing an MOS that will be related to my future goal (medical, long term as a PA or flight nurse)? I appreciate any input. Thank You!