Some people are advocates of thermals for stalking...some less so...but we have been out using the new Guide IR517V Pro thermal spotter which has a 640x480 sensor, and 1280x920 display, providing twice the resolution of my previous device the Quantum XD50S and considerably better identification.
With a 640x480 sensor, wifi, video recording, GPS and interchangeable lenses 35mm, 65mm, 80mm, you have a 2200m max detection range, with a stunning resolution.
Its not cheap, but at £5300 its considerably cheaper than anything else on the market that comes close to the performance and features, take a Thermoteknix TiCam 600 at £15k which side by side to this wasn't mind blowingly better, (although mil spec build) and in fact was comparable at best in terms of image quality.
Blown away with the performance of this unit and I've used a lot of thermal kit.
Heres a little video of it in action on a lovely wee buck using the smaller 35mm lens.
More details here on the unit