The horse is the 2014 Mojo Fun Suffolk Punch Mare, sculpted by our own Anna here on forum.
Torben's site is the best reference for figures: http://www.schleichtiersammler.de/
Tiewe.de is another good one.
And don't forget TAI! http://toyanimal.info//index.php?title=Main_Page
Your last question is a little hard to answer. Schleich does come out with SEs now and then, some are produced in a limited number. Long-retired figures are sometimes hard to find, others not. It really depends on where you're looking and what you're looking for. The superbeagle and superpinto are very highly sought-after Schleich figures, is are the WWF series.