I would have to say AmsOil here too...been using their products for about 8 years and i love only having to change my oil 1x a year. I am getting ready to become a dealer as well for OKC. My vehicles run extremely smooth and don't have any probs in the cold weather starting up (granted it's not Alaska but still)
Would love to help you out more if you'd like. Just pm me. Take care and best of luck!