Thanks for the responses guys. I am hoping the 2 cannisters will fit AND be enough.
wright4lfe: The acrylic is pretty thick, it would probably be a PITA to cut another access hole. I was thinking I may just squeeze both cannisters into the overflow hole and have a powerhead on the opposite side of the tank.
Anyone have a link to a sump building guide with pics? Tried searching, but there's a lot to look through. I like the idea of a sump, but also don't really have the space, the tank is tall and will be going on a pretty short stand, I'm not sure if there is enough room.