Some good suggestions here already from members. But if you are going to be ranging 2500 meters, you will need some expensive kit to make anything happen at that range. A RPR rifle won't touch that distance. You will need a ChevTac or something that will really reach out and touch. 1609 meters is a mile.
What it sounds like you need in my opinion is just a sig kilo2000. It will range anything you will be able to shoot with 308, 6.5, 300 win, etc, etc. If your going to actually be needing to range and shoot targets farther, you will need to put it on a good tripod, etc. I think a kilo 2000 is perfect, cost effective and works for 99.999 percent of shooting. And you can find lightly used ones pop up sometimes for 200 bucks. The sig 2200 as mentioned is a really good rangefinder also.