I'm looking for a high magnification set of binos for long range hunting. I want to mount them on a tripod for glassing side hills in Pa from 600-1500 yards. Does any one have any experience with the Vortex Kibab 15x vs the 20x? I also saw Celestron make a Sky master 20x80 set of binoculars. Has anyone ever looked though a pair of these? Im on a budget so please understand I cant do the swaros or high end glass right now.