My concern with letting people pick 2 because they have a higher rating is this.

Say yours is an 8, and there are 2 - 3's and a 2 that you want. Lets also assume this is in the early stages where there are not allot of deposits, maybe 10. If you were allowed to take those 3, we would have two others that couldn't book. That concerns me a bit.

How about this? This may be the answer to both of your questions.
Once your inside a, say, 60 day window (or 45, or 30), it opens up. Allowing all hunters to pick from all trips. In other words an 8 could pick a 10 (this would keep trips from going unused).

We could also, in the same time frame run specials, where you got to pick 2 for 1's.

Again allowing what might go unused, to be used. That way it's not taking away from someone that was going to book it as there 1 for 1?