Where do you live in Canada...if your in the GTA your welcome to come over and audition my sub. I went with funkywaves for my current sub and would highly recommend him. With your set budget your probally looking at one of his fw12.x designs. I was told that sub was designed to compete with the pb12 plus here in Canada and would very likely surpass it. I personally can't wait as we'll see those results after the ultimate sub shootout...
PS: You have nothing to lose if you send him an Email..see what he has to say.