ICS-100 is usually taken online, as is NIMS-700. 200 can be taken online, but if you want to go beyond that, you have to take the classroom version. ICS-300 and 400 are classroom only, but unless you're a senior officer, you're unlikely to need then.
Check the local fire academies, fire makes much more use of ICS than EMS, from my purely anecdotal experience.