I've gone through a few bi-pods. I have a question for you, what is the primary use? I mean, do you intend to be using this where you will be carrying the gun a lot or using many different set ups like changing distance a lot? Or will it just be at the range and at one or two distances during a shooting session?
I ask because I've found I like a bag better under most circumstances. If I'm sighting in at 100 yards, I find the bag to be just a tad easier to use. If I'm going to take one shot each at 100 yard intervals from 100-800 yards, then the bi-pod is less stuff to move.
If you are set on the bi-pod, I really like the one from Green Blob (yes, it's a real company):
Comes with a quick release picatinny mount and only costs $39. Can't go wrong with that unless you're in a serious long range competition.