hey Troy - u know about Michael Hedges huh (RIP) :'( yeah his stuff was as advanced as u can get almost. I have a idea for u which totally advanced my playing - listen to a old guitar piece by Steve Howe of Yes its called The Clap - Im sure its on youtube. Also - Stephanie by Lindsey Buckingham - its on his 1st release called Buckingham Nicks. Embryonic Journey by Jorma Kaukonen (Jefferson Airplane) U could try Black Mountain Side by Jimmy Page but that's tuff. I cant think of any acoustic pieces evryone knows - lol they're not pop music, strictly guitar.
email me if u wanna chat some ok
The best answer I can give you on this is a guy names Derek Coombs. I just recently learned about him and his guitar pieces are great. Just GOOGLE his name and click on the link that says Background. Some great pieces of his are Morning Walk, A Kiss in the Night, and Breeze. Their very cool pieces for acoustic guitar, and you should deffinately check them out.