Hey chp201, I am playing from Canada so there will be differences. Nationally we have 4 levels:
Emergency Medical Responder - would be similar to US First Responder
Primary Care Paramedic (BLS) - would be somewhere between the US EMT and Advanced
Advanced Care Paramedic (ALS) - previously known as EMT-P
Critical Care Paramedic (Flights & Community Care) - Specially trained for specialized environments.
My suggestion would be to create an Advanced Care Paramedic qualification that would be required to staff ALS Ambulances
As far as remember, this feature was asked for the very first EMS Content Pack, few years ago (that CP with BLS Ambulance / ABCDE Protocols, etc...). At this time, the dev team refused to add an "EMS academy" with ALS / BLS training. So we just have ALS and BLS Ambulances. I don't know if this thing will change from now.
Another thing to take into consideration is, the actual EMS CP is a Part 1 (out of ??? parts). Unfortunately they don't want to tell us what they are cooking at on the following parts....