Depends on the "big" city. Some cities have FF/EMTs work on ambulances, so then you have to compete with guys who want to be FFs so bad, they'll say and do anything (including EMS) to do it. Then some cities only hire paramedics to staff ambulances. Then there are the ones where private ambulances transport where EMT jobs are dime-a-dozen. My city has EMTs who are not FFs, and judging by how bad so many of them are, it must be pretty easy to get hired. Another city, where I worked as a medic, had great EMTs, and to get a job as an EMT was actually pretty hard. For a better idea of what you're getting yourself into, just name the cities you're interested in and people here will let you know what they know.