Whew, i don't think you are going to be able find what you are looking for. 4 stroke mopeds are pretty rare, and generally underpowered. We may be foreced into them with EPA regs, but we won't be happy.
Something to consider besides the 2 speeds is the variated peds. They have variable speed belt driven trannies and are supposed to be good on hills. ( I don't have one running yet)
Are you up for wrenching on an older one? If you are looking for a newer ped you'll be more limited.
No matter what you buy you'll need to learn to take care of it...Not a lot of dealers in Montana. Good luck.