Hard request to answer without more info. What ranges? Open range or cover? I prefer Nikon brand, but there are others that have great reputations. Mounts? A PEPR is hard to beat but a bit pricey. Weaver has a mount that is very similar for half the cost. I use both and either is great. I assume you aren't needing night vision?
There's a fine line between BRAVE ... and STUPID.
The two most important days in your life are the day you are born and the day you find out why.