Do you already have a camera system? It seems that the photosniper is a whole kit with camera, lens, and stock. The camera and lens quality would be questionable.
If you already have a nice camera setup, how about just purchasing a "rifle" stock like this:
Hey ermetekos, are you still interested in Zenit Photosniper? I have the whole package of Zenit 12S for sale. I guess the camera has never been shot since it is in its brand new wrappings. The package contains filter lenses, photosniper equipment, and the basic lens. Contact me if you are interested tatu(at)adkiivi.fi.