What is your time frame, that will help people frame their answers better.
Running: Starting out right now try to run/walk 2-3 miles twice a week until you can get a consistent pace where you no longer have to walk. 400m/800m intervals at your goal pace 1-2x per week. So if you are shooting for a 16:00 2 mile, then you want to run your 400m in 2 minutes, and 800m in 4 minutes. Take your rest in a 1:1 or 1:2 ratio when those get easier then lessen your rests.
How many push-ups are you able to do currently? Be completely honest with yourself, are you doing these push-ups to Army standard?? I've seen way too many people that think they knew how to do pushups.
With running 3-4 times per week I'd limit gym time to twice a week, focusing on total body both days, one pull day(deadlift variations, weighted pullups, rows...etc), one push day(squat variations, bench, weighted pushups, dips, overhead pressing). That is a very general outline and the intricacies lay upon how much time you will have available prior to shipping out?
Supplements: You haven't mentioned nutrition so I'd place a strong emphasis on that aspect before worrying about HOT-ROX, pre workout nutrition, post workout nutrition...etc. Dialed in nutrition trumps adding X number of supplements any day. Flameout or some other fish oil product is what I'd recommend above all else.
Off topic slightly:
Why do you want to be an MP? Not a knock, I'm an MP, but what are you looking to get out of joining the as an MP?