Sure. If you're not familiar with flat wound, then the strings you are used to are round wound. If you look really closely, you can see the ridges because the outer wire is round. This is cheaper and easier but produces a string more prone to noise as you rub along the ridges. With flat wound, the outer wire is a ribbon wrapped around the inner core with the flat side out so you end up with a string much smoother. It's also generally stiffer and with a tone not as bright.
If you can get on his schedule, I highly recommend Jonathan Dale. AFAIK, his prices are still a good bit under your budget and he can make the string spacing however you like. I know he does 19" or 20" and like I said, Terz is easily achieved with standard classical guitar sets.
If you want to try a narrow 19" for a whole lot less, try the Cordoba C1m 1/4 size. Elderly lists it for $159 but out of stock. It's laminate so a little on the quiet side but not a bad sound at all.
I have some videos on both. I can find and post the links if you're interested.
I would like to see the videos, when you have time.