I'm looking for preferably a hollow (inflatable is my 2nd choice; no to 2-D) seated/breeding position Rio Grande hen decoy. Any in particular I should check out?

Dave Smith Decoys are about the best. Avian X after that.

A DSD upright hen oughta do the trick. Yep.

Put it on the stake for general duty. Set it on the ground without the stake for breeding scenarios.