I use a Shooter's Ridge "Steady-Pod" for all my big game hunting. I have the one that adjusts from 26-64". It allows me to sit on a stool and hunt comfortably over a field or watering hole and, extended, it carries easily through the bush, for those standing shots when cover is high.
It has a cradle attached to it that holds the forestock quite securely. Wholesale Sports has them.
On my coyote rig, I have an attached bipod that extends from 14-40". I can't remember who makes it though.
Hard to find a decent one even for sitting on the ground. Being tall this precludes the 23" bipods one finds so common in shops.