Hi Froggy:
Welcome to our forum. Let me give you a few answers while the other more experienced folks add on more:
1) what kind of Arrow frogs are best fit for a 10 gallon tall? nothing ive read so far specifies tank size!! and can i get them in canada (names, numbers or websites???) A: actually, just about everything in darts I've researched from the thumbnails to the larger Dendrobates or Phylobates are ok as a pair in the 10 gal. Many breeders use such a size for pairs. They'd certainly be more comfortable in something a little larger, but its not entirely necessary. Breeding will go on in this size as well. Of course the more animals you keep in one tank the larger the tank. General rule that I have seen used: 10 gal for the first frog, additional 5 for each additional frog. understory.com is in canada.
2) EXACTLY how poisonus are these guys, like say a cat were to eat one (dont worry i dont even have a cat) and are they poisonous to the toutch (again dont worry i wouldnt be wanting to toutch it.) A: The captive born(CB)are not poisonous. In the wild, the diet of a Dart is what produces the poisons. But in captivity, their diet is controlled so you won't be seeing stars. If a kid were to eat one, I'd be more concerned about other things...perhaps samonella?
3) can they eat small mealworms? or are they to big for them? A: The mini-meal worms are small enough for my Tincs. but my Thumbnails I'm not sure. The minis are 1/4 in. But meal worms are said to be too fatty for a staple. You'll need to culture fruit flies like the rest of us for a staple. Other treats could be Springtails, Aphids, ants, flour moth larve, whiteflies, silkworms, and now a new source being experimented with are the Milkweed bugs.
4) finally, do they need flourescent lighting? and could i use an incandescent hood with those new "energy saving" bulbs? will my plants continue to grow under those? A: to my limited understanding on the lighting issue, incandescent produces too much heat. Course in the winter that may be welcome but it will be hard to control in the hotter months. Many of us use Compact florescent for mostly the health of the plants. And I have found that the health of my plants actually affect my Tincs behavior. She is much livlier, bolder with a healthy bountiful growth.
Many breeder sites will go into more detail about all your questions so just point your browser to the top and a number of sites can direct you through your research.