Maxcast, Phil Keaggy is great. I have lots of his music--not all. Beyond nature is a classic for that style; Lights of Madrid is along the same lines, with some songs having orchestral backing. He is also an exceptional electric guitarist. One CD to pick up is The wind and the wheat; some songs are electric, some are acoustic. One thing, though; Keaggy is a devout Christian, and his songs on the vocal LP's all reflect that. Not being critical, everyone's beliefs are fine, but some people may be put off by that, and stick to the instrumental albums.
If I can make another recommendation, try to pick up a CD by Tom Yoder called Eat this it's safe; it may be hard to find, it's an independent release. I'm biased--Tom is my best friend from high school--but one cut was a finalist for best new age acoustic song in the Independent Music Awards, and his music has been used in the NPR All things considered show. All instrumental acoustic, closer to Leo Kottke than Keaggy, IMO.