Imaris, you might like to listen to this, it's quite intense. It's an instrumental side project by members of Dream Theater.
I can't say for sure about albums, but if you want something around twenty minutes long, I can recommend something from this list:
Dream Theater - A Change of Seasons
Dream Theater - Octavarium
Dream Theater - The Count of Tuscany
Symphony X - The Odyssey
Of course, it's not a solo for the entire song, but there's something to listen to. In general, I don't really like very long solos. Or rather, I do, but not just any - I prefer when it's not just one solo, but several).
To sell my soul