Hey carpcatcher. Welcome to the sport.
There's a few places to get your gear.
http://www.fdarchery.com/
is one.
http://www.bowfishingextreme.com/
is another, and
http://www.backwaterbowfishing.com/is another. Any or all of them should have whatever you're looking for.
For setting up a traditional bow without any of the holes drilled and tapped in the riser, you'll need atraditional mount, found on this page;
http://www.bowfishingextreme.com/ItemsForSale/ReelSeats/bowfishing%20reel%20seats.htm
This will allow you to mount either a Retriever-reel to the side of your bow, or a reel-seat and spincast-reel to the front of your bow, without drilling holes in your bow.
Next, get you at least 2 arrows with safety-slides or stainless-steel rings to tie your line to. You really don't want to tie yourline to the back of the arrow because when you draw, the string will come back past your rest and have a chance to get tangled on it, or your cables, and snap back in your face upon release.
The more popular spincast-reels are the ones with the bigger holes in the face to accomodate the thicker line you'll be using. Muzzy has a good one out, as well as Zebco (808 or 888, I forget which is better) and the Shakespeare TI-20. Just gotta remember to push the release-button before you shoot. Your reel will last alot longer. And if you go with the spincast setup, get a good reel-seat, like the blue one from Muzzy, or the black and gold one from Cajun. You'll see them both on the above-page with the traditional-mount.
Hope this helps. Good luck and post pics when you shoot some.
Almost forgot; you need some heads on those arrows. I think it's safe to say that Muzzy is pretty popular and easy to use. When thehead goes through a fish, just give the tip a turn or two, reverse the barbs and slide the arrow out. Turn the barbs back down, tighten up the tip and you're back in the fish.