Caddy were almost the same as mine and apart from the poor customer service I had from Caddy in Melbourne I wouldn't write them off. They make most of the canopies for Coles maintenance utes and they are a strong canopy. I wouldn't mind betting they come out of either the same or a similar factory to Avenger.
As for buying, I'm guessing your only looking at second hand therefore your best choice is ebay, they come up here occasionally but not very often. having said that 3 will probably get posted tomorrow!