You won't be designing it if you just copy the schematic of somebody else.
At 200MHz you would cause and receive interference from TV stations and legal communication services. It is against the law to cause interference. If they interfere with your radio then it is your problem because they had the frequency first and are licenced for it.
It would be easy to make a poor quality low power mono FM transmitter.
If you can find the parts, you could make a mono FM radio with transistors like were made in the sixties.
