I believe every state requires you to have at least a high school diploma. Being an EMT is great...but did you know what there are several different levels of EMTs? Here in the state I live in, there are EMT-Basics, EMT-Intermediates, and EMT-Paramedics.
Why shoot for the bottom level? Why not shoot for the top and become a degreed Paramedic? There are a few colleges out there that offer bachelor degrees in prehospital emergency medicine. EMT-Basics are important, but when you look at the amount of education they have...it's just a simpe 8th grade first-aid class type stuff.
Do you want to be in the action and stuff when it comes to procedures...like putting breathing tubes down people's throats or decompressing a flail chest? If so...you better get your Paramedic, 'cause NO EMT-Basic will ever do that type of stuff.
I suggest you get a Paramedic degree and work for a 911 ambulance service. I do not reccomend joining the military. Most people will end up economically worse after joining the military.