Getting a 2-stroke machine isn't all that difficult, but you are right to worry about maintenance. While authorized dealers are unlikely to agree to service them, considering these bikes have been around for so long, you should be able to find a trustworthy local mechanic.
Between the Suzuki Max 100 R and the Kawasaki KB100, the former will be easier to find service technicians for, as it was quite a popular machine owing to its hardy workhorse nature back in its time.
And just so you're on the right track, the Hero Honda CD100SS was powered by a 4-stroke engine.

