You might want to take a look at Panasonic's lineup:
The BB-HCM511A is a megapixel IP camera with remote pan/tilt, digital zoom, that has a built-in webserver, versatile interface, and SD card recording capability. Best of all, it has power over Ethernet (PoE) capability, which greatly simplifies installation, since you won't need an electrical source nearby. I believe that 300 meters is the limit for such Ethernet runs, so your 500 foot perimeter should be OK. This model is not for outdoor use, but Panasonic has others that are.
I've installed a number of these, and it produces excellent images, and is very reliable. Like most IP cams, however, they don't provide good coverage in darkness without IR illumination. They retail for about $459 each, but can be found for a good deal less "on the street."
Good luck