I have a quick question. Can anyone tell me the transmission properties of 1.2Ghz versus 2.4Ghz?
Despite the doubling of frequency, the two bands are remarkably similar in propagation - the signals are stopped by metal, water (the water in the leaves of trees will attenuate signals at that frequency), and solid objects like hills. With relatively high gain antennas (easy to do at those frequencies), you should be able to easily cover 500 yards, IF it's line of sight, with any of the 2.4 GHz transmitters you can find online, or through Boostervision (you've already been given the URL).
BTW - best check with your local game wardens - remote spotting/target aquisition is not legal in all states (thanks to some jerks that did an internet accessible "big game hunt" where the "hunters" remotely manipulated a video camera that was sighted in on a hunting rifle and were able to remotely "shoot" the weapon).