Dude, if you want some really nice acoustic stuff, just play minor chords and play with them. I'll post a video later of what I mean. Take Em as your start. From there you can add G, D, Asus,, Dm, Am, C/F etc.
Some really good acoustic stuff is done by Zakk Wylde. If you are one to solicit pirate material, try and find Book Of Shadows. By a mile one of the best pieces of acoustic work I have ever come across.