Welcome to our world. May I recommend you look into joining the VCI-Group (http://www.vci-group.org) as one of the first steps to learning about the industry.
The Polycom ViewStation (VS) product line is about 4 generations back, was replaced by the VSX, then Polycom added the HDX and in October of 2012 added the RealPresence Group. There would not be any of the VS products available as new product but a place like e-Bay would be a place to look. Moving NTSC units (TV standard used in NA and Japan) to a PAL country (most of the rest of the world including Europe) would not work well. Besides the differences in the TV standard there would be the issue of the units markings for proper importation into that country.
Depending on your requirements the current low end product lines would be the HDX 6000 (single display only), the HDX 7000 and the most recent RealPresence Group 300. Please look at the Polycom web site for details on the current product line or contact a Polycom distributor for a briefing on the Polycom product lines.