Its hard to put Exodus into one category given the variety of songs. The more energetic songs (Go, Wonders of You, Radiate, Amazing, etc..) I would classify as some hyrbrid of progressive house and trance. The synths and effects and use of vocals are very reminiscent of Trance while the drum beats and bass lines have a very progressive feel that is closer to progressive house music. The less energetic tracks (Show, Translucent) are straight up ambient electronic music. Like most ambient music, use of drums and bass are greatly subdued, and the emphasis is on lots of airy synths and vocals.
Andy Hunter is one of those artists who is hard to fit into specific genre. I have found i have a deep respect for artists who branch out and make music unlike anything else and are therefore very hard to put into one nice happy category. Classic examples of this are Radiohead (the new album is amazing by the way...), and Dave Matthews Band (jazz infused rock or rock infused jazz?) In terms of electronic artists, there is quite a range of artists that are hard to pin down. Some examples are BT (Trance & Progressive Techno etc..), Daft Punk (House & Techno), and more recently Paul van Dyk (his new album is also amazing) If you take a listen to each of these artists, you find several similarities, there is a wide variety of types of songs, their style progresses with time, and they are leaders in scene. I believe Andy Hunter is most similar artists because he develops his own style that is constantly progressing. By not conforming to a genre, the music of such artists sounds very new and fresh... which is why they keep developing as artists because what sounded fresh 3 years ago is now a common style. I usually like to describe Andy Hunter's music as a cross between BT and Paul van Dyk with a little Crystal Method thrown in the mix.
In terms of other Christian DJ/Producers like Andy Hunter.... there aren't any others. At least as far as I know. Andy Hunter is the leading Christian DJ/Producer. It is my dream to someday join the ranks as a Christian DJ and Trance/House Producer. But right now I have no time or money due my status as a student studying to become an architect.
Hope this helps :)