To the OP, and a couple of other people, the military does accept non citizens, and you can gain citizenship this way. I was in basic training with some guys from other countries.
Now to the question, your recruiter should know, or be able to find out for you. But failing that even, the recruiter normally can take you to MEPS (Military Entrance Processing Station). They either fly you down, or drive you there, after you feel out some paperwork for your recruiter. The recruiter sends all that paperwork in, then gets back to you with an answer. He may need more documentation etc from you, or have more papers for you to fill out, or he may come back with a negative answer. Just about everything can be waived though, especially in the Army.
Two year or four year enlistment is ideal, but the Army and any armed forces in the states can recall you back in. You basically sign up for a commitment of 8 years. If you serve 2, then you have 6 years of retainability where they call you, and you have to go back on Active Duty. There is no way around that part of signing up.
But just fill out what your recruiter asks you. Nothing is Final until you go to MEPS and get a medical exam, and then sign up at the MEPS and swear in. You can still back out anytime before the swearing in part.