newbie with skimmer questions!

ok so this is my first saltwater venture. I've been doing some research and decided I was going to build my own sump. I found a 10 gal tank that will fit in my stand, but before I start building the sump I'd like to have the skimmer so I know where to put the dividers.
anyways...I started looking at skimmers online and the choices are overwhelming!!! I seen some from $35 and $50 all the way up to several hundred. I've got a 55 gal. aquarium, so how big of a skimmer do I need?? what is the best type (venturi, counter current, etc). keep in mind I'm getting into this hobby on a budget, so anywhere I can save some $$$ without getting junk equipment would be great.
for example would I be screwed if I bought something like this.
Visi Jet Protein Skimmer I know its cheap, but would it get the job done? would that 100 gph pump not keep up? my total sump system should flow 300+ gph I think.

 

I would recommend the Coralife 65. It's on the cheap end but still a pretty good quality skimmer.