good cause fees for shipping to canada are lame lol.
if its a q3000-12 then the rms they give says 1000 but even that seems made up given the price of the sub.
http://www.sonicelectronix.com/item_67933_Hifonics-Brutus-BRX1100.1D.html is a good reliable option.
i can't be 100% on any of this and just tell you what i would do. quantum audio is a budget brand that doesn't worry about being cea-2006 compliant and just make up numbers for their stuff.
i figure that amp should last long past when your current subwoofer dies and its a good enough quality amp to put a fairly nice subwoofer on.
what gauge wire you running to the current amp? you having light dim problems at all with the current low power amp?