A 50# recurve should work fine. There are alot of good ones out there and there are usally some good buys on E-bay if you keep a eye out.
As far as reels I and alot of other us Shakespeare Synergy 4002's and Zebco 808's and 888's. These mount to your bow via a reel seat that screws into your stibilize hole. If you have no stabilizer insert they also make side mounts that screw into your sight area.
Arrows... a plain old fiberglass shaft with either a Muzzy carp or gar tip, Muzzy Stingray, or sure shot penetrator will do the job. Its usually better just to shoot off the shelf of your bow. For line 200# Fast Flight is recommended for the spincast reels.
You can check out
www.sullysbowfishing.com for equiptment and a good site to check out for bowfishing in general is
www.bowfishusa.com