If you want to run a pump, you'll need the grounded modules (trust me on this one). even my little itty bitty via-aqua that I use for top-offs wouldn't fire off of the "lamp" modules.
The grounded modules come in many varieties, but the most common is the 110V/15a module that you'll find at Radio Shack. The only place I've ever found the 110v/20a modules is from X10 itself.