Get a 88 or later, the 87 can have CDI problems, although I have had no problems with mine. Earlier models had kick starters, later models didn't. You want a kicker. Earlier models had drum front brakes, later models have disc. Really no difference in them in my opinion. Procycle has a great page with stuff for TWs.
Yes, TWs are lots of fun and you can do a lot with them to make a great adventure bike.
Welcome to the forum Bob, you will enjoy the simplicity of a TW.
Yamaha TW200 Parts and Performance - ProCycle