RE: Rest
Like justabout every aspect of bowfishing, its a matter of personal preference. Many trad bowfishermen prefer shooting off the shelf because of its inherent anti-snag qualities and simplicity.
If you are looking for an actual rest to mount on a fishing bow, there are a fair amount of styles to choose from. Most are a form of roller, hook, eye, or 'V', although some guys get by with a simple flipper. There is even a Whisker Biscuit for fishing. Most of these restsare quite inexpensive compared to the ones you may use for target shooting or hunting.
Check out some from F&D archery, AMS, and see lots of pics at Sully's.
Hog Killer,
Do you shoot fish now?
What kind of bow do you have/want?
Where do you bowfish?
What do you normally catch in your area?
-Bulz