Basically what I posted in another thread:
You can buy from a big store like Cabela's or Bass Pro, most of the prices are a little higher, but the bowfishing arrows seem to be really overpriced. Lots of stores aren't too great because they provide free shipping to US residents but either they won't ship here or it'll be too expensive to be worth it. The best shop I found that would ship to Canada through USPS was bowfishingextreme. Arrows are fairly cheap ($10 with arrowhead carp points), safety slides $3 each, spare retriever lines $10ish, retriever system around $80, etc. Shipping comes out to around $40 so as long as you order all the things you'll need and some spares it'll be worth it still (spare arrows, definitely spare points, line, etc).
As for bow, you can use pretty much any compound bow. They do have "bowfishing" models (just some blue paint on it lol. I got mine on archerytalk. It's a diamond razor edge (19-29" draw, 30-60lb). For a complete package it was $240 US, due to a store clearing it out, retail it's $330. You can just use an old bow you got laying around or a cheap recurve or compound you can find, but you can go as big as you want. :razz:
Make sure to check the legality of discharging a bow anywhere you plan to shoot; municipal by-law restricting the discharge of a bow. And I've always had the fishing regs on me or in the vehicle (though usually for all fishing).