Re: range finder advice
Buy the furthest ranging model that you can get/afford.
I don't personally have any experience with the leupold models, but I have a bushnell 800 yd model. It will not range small targets to 800 yds, only about 500 yds.
I've also got two Leica's 1200 and 1600. Neither of them range very small things at the full advertised distance either.
Get more than you think you will need, you won't regret it.
Aim small = Miss small