Your recruiter is the best source of information
First, the choosing of an MOS is not one of the first things you need to consider in choosing the Marines. Let the recruiter understand your goals and needs. Allow him to explain the general benefits associated with Marine Corps service. Once you are satisfied that the Marine Corps will improve your position for the future,, you will need to take an ASVAB Test and physical examination to determine your eligibility for USMC service and MOSs. Active duty will offer you far more MOSs to choose from. Reserve MOSs are limited to the needs of the Reserve unit you are joining. The MOS is always secondary. Being a Marine first is the primary concern.
SF
It sounds like a good plan
I think you have made some wise decisions based on the information you have gotten. The reserve route is a good move. If, and I mean it, if you decide to go Active Duty, look into new opportunities/MOSs at that time. Should you want to go the officer route, remember most OCS grads will become ground officers. Having a background in the infantry will not be a bad thing either. I hope you do join the team.
P.S. I may be twice your age, or old enough to be your father, so listen to my wisdom.... become a Marine!!!