Hey fella's...
I am a professional woodworker/custom furniture maker by trade. I build guitars for fun - but making and finishing furniture is my living. The best places to get industrial quality finishing products (like lacquers, various stains, selaers, etc) are not the home depot type shops but the places that supply guys like me. You should look up finishing supply companies (for instance, John E. Goudey in Toronto) that manufacture the stuff, tell them what you want to do with it and let them guide you. Personally, I use a post catalyzed acid cure lacquer, and its tough as a polyurethane, applies as easily as a lacquer but is kind of nasty stuff. Not something you want to spray in the house. Any industrial type finish (ala automotive urethanes for example, or the stuff I am talking about) are meant to be sprayed in a proper paint booth with protective equipment so you dont harm you lungs... safety stuff aside, I suggest you try either a commercial distributer, or check out some furniture shops (if there are around where you live) and see what they use, and if they will sell some. I do, but only to guys I know know how to properly use it. Also, ALL this stuff is hazardous materials and will not be able to go by purolator, canada post, etc. Only private couriers or transport companies will touch the stuff.
Hope that helps some...
AJC