Will a infantry mos open up before i ship?

ok i have a few questions. im in the dep with the usmc and right now my mos is engineer equipment mechanic and i want to change it to infantry spec 0311 or 0313 but they are full so do you think a infantry job will open up before i ship aug 23rd 2010 and if not whats some simmilar mos's thinking combat engineer is my 2nd choice also i really want to get to go to afghanistan so do you think i will get the chance to go or will everything be over with before i get to go? and is there a mos or anything i can do to increase my chances to go?