Thanks so much for your input!! You guys have given me a lot to think about and research. The WR250 really stood out in many posts, so I'll take a look at that (and others that were mentioned) and I'm definitely gonna get used vs. new.
I was just always under the impression that 250's were underpowered for the highway, but I don't know why I thought that. That's why I was looking at 400cc and above.