Ive got to agree with Thomas. I use the Canadian version of the RBI 12 quart rack and it has served me quite well so far. The PVC seems like it will last much longer than melamine. I also really like that RBI provides the tubs for you, as well that they are IRIS tubs, which means they are flat at the bottom and very easy to clean. And pretty sturdy as well.
Ive heard amazing things about animal plastics too, and I wish I could get one, but I just live too far for it to be worth it. Boaphile also makes some amazing racks, but Ive heard you should be prepared for a decent wait time. In the future, if my breeding ever gets to the level where I could afford a freedom breeder rack, I think those would be my preferred rack system. They look so nice and clean!
Edit: Vision also makes some really nice tubs, I would highly consider building a rack just to put some vision tubs in it, if they shipped to Canada.