Lyn, Welcome to FGRV! Good luck with your hunt. David offers good advice. There is a classifieds listing here on FGRV. You can also use searchtempest.com to scan multiple Craigs List listings near you (or further away as your fancy takes you.)
Also, on the molded fiberglass for sale
page, you can look for those available in Canada. It is possible, and fairly painless, to bring one to the US from Canada.
Again, good luck and feel free to ask questions as you go along.
BTW, there is a Buyer's checklist in the documents section of this fgrv community.