Another person to check out is Steve Hackett, who was the former guitar player from Genesis, especially his first album.
Also, there was a very short-lived group that he and Steve Howe (Yes) formed in the early 1990s called GTR. They only released on album - titled GTR - and it was pretty good, in my estimation.
Another group that you should consider listening to is Kansas, of "Carry On My Wayward Son" fame. Albums like Leftoverture, Point of Know Return, Song for America are a fusion of prog rock, country, and classical music. They are one of my favorites in this area.