I have dove with Discovery Diving numerous times and have always had a safe and fun time. http://discoverydiving.com/
I have stayed at Discovery’s "Dive Lodge" before. No fluff but fully functional and for $25 a night I found it saved me some $.
Olympus and Discovery are really the two well known and respected operators in the area. You can’t go wrong with either of them.
Have fun, I highly recommend the U-352 sub and the Spar where you usually see some great Sand Tiger sharks.
Randy