[Starchy]

We want to install a simple water feature consisting of 2 small stacked preformed plastic "pails" containing a very small pump, similar to a small aquarium pump. This is a unit we purchased. The pump runs on 110V, probably less than 5 or 6 amps, if that. I have located this water feature on a flat stone on top of the exit point of a 4" diameter black palstic underground pipe that carries water away from the house from the eaves trough downspout. This pipe would provide very easy route to thread the 110V cable to this water feature. I would want to exit the downspout at the house to pass through the wall, where I would install a GFCI in a 110V box.
1. Is this doable? Or do I have to trench and lay some sort of conduit to carry the cable?
2. What type of wire do I need to buy for a 28 ft run?
3. At the end of the run, do I have to install a post and box to connect the little pump? It currently has a standard 110V plug on the end.
Any help would be greatly appreciated. Thanks in advance.