All surface skimmers are basically the same design. It spills water into a box, pulling from the surface to get the proteins that float on top, and siphons from the box into the sump. We used to call them anti-siphon boxes. This is because if the power is cut to your return pump, the siphon will break after it empties the box which will keep your tank from siphoning too much into the sump and spilling all over your floor.
No pump is needed to use the skimmer, but yes you will obviously need one to feed your tank from the sump.
I don't use one personally as my tank is drilled. You may want to start another thread asking which surface skimmer is the best in the lighting, filtration, and equipment forum. I'm sure you will get some more specific advise. Or, maybe someone will chime in on this, you never know.
hth