The Patrol XR 250 60mm is an outstanding long range thermal. However, for a helmet mounted Thermal paired with a PVS 14 it is not a very realistic Thermal to use that away for the following reasons.
1. Native Magnification is 4.5 X
2. FOV is 7 Degrees
3. Weight is 27 oz or 1.68 pounds
Trying to pair a Patrol XR 250 60 mm with a PVS 14 is almost equivalent to trying to pair up a F16 fighter plane to fly with a Kite. Just wont realistically work such that a user would be very happy and satisfied.
First thing the setup will be very unbalanced due the the XR at 27 ounces vs about 12 oz for a PVS 14 is almost twice as heavy and your helmet will be listing over to the side the XR is mounted on or your neck muscles will be fighting to keep your helmet straight or you will have to put side counterweights on the PVS 14 side to balance that configuration up.
Second, the XR's FOV at 7 Degrees is really just too narrow for a helmet Thermal Scanner.
IMHO a helmet mounted Thermal Scanner needs to be approximately the same Size, Weight as the PVS 14 such that a system is balanced correctly. About the only Thermal Devices I know of that currently fit that bill are the Flir Breach, Skeet, MTM or Tilo 3Z or ATN Odin. Out of those the Skeet is undoubtedly the best but very expensive and the cost to performance benefit ratio is not there for me. For someone with tons of cash to spend, hell yea, do it. It will give you an outstanding image but still is only a 1x Native Magnification device (albeit 640 x 480 at 28 Degrees) as are all of the above mentioned devices.
All of that being said, realistic helmet thermal devices are all only going to give you a marginal distance of Positive ID on live animals. The primary function of a helmet mounted Thermal is simply to let you be able to scan 24/7 as you move along such that you can detect that a live critter is out there. Once detection is achieved then you basically have the following choices.
1. Throw up a much more powerful Thermal such as a handheld or weapons mounted that can reach much further out and give you the ability to Positive ID at longer distances.
2. Throw a 3x or 5x Magnifier on a PVS 14 and light the critter of interest up with IR light (Luna Elir 3) works very well, (but don't focus beam energy too narrow and smoke critters eyes, unless its a hog, LOL), such that you can get a true visual on critter.
3. Walk your ass off such that you get close enough to critter to Postive ID with a 1x helmet mounted Thermal.
IMHO, the best current affordable setup that will do a really good job is take a Flir Breach and pair it with a PVS 14 using the Mod Armory Lite Weight Bridge with a Mod Armory Breach Arm correctly adjusted for alignment with the PVS 14. Use a Norotos Rhino 2 with a Dovetail Socket. Get yourself a good weapons mounted Thermal such as a Flir PTS 536 and you are now a hog killing machine. Breach lets you know critter is out there 24/7 and PTS 536 will give you Positive ID a long way out and dispatch critter if so desired.
You can buy all of that for less than the price of 1 Patrol XR 60 mm or 1 Skeet and run just as effectively as any setup out there except maybe some secret squirrel stuff civi's can't readily or realistically get their paws on.
Unfortunately, in the NV, Thermal game there is not a 1 fits all, does it all device. It takes a multi level of devices to assemble an effective and cost efficient total package to get it done.
Hope this IHMO information is of some use to you in making your decisions