+1. I think you should contact Eric West directly or Dave Davidson - they know about CNBG and their cold tolerances. I have no clue about their chances in Oklahoma....but they will.
Also, that 90% female claim cannot be accurate IMO. I would strongly consider contacting a new hatchery as this is a troubling statement coming from a fisheries professional....
If you want lots of BG with great genetics give me a call a few days before you drive up here to beautiful NE. I can probably get 500 in a week - all feed trained CSBG.