those all look good, but they all seem to be loader based.
my idea of a mirror is that i will use it a lot under a wide variety of conditions when the loader may be off. the one that springs immediately to mind is when mowing around the house and i need to be wary of any small pets or children behind and around me. ideally i would like the mirror(s) to be mounted low where it won't easily snag on things but still be able to see it easily from the seat and have it stay attached to the tractor with or without the loader.
i don't think the "dash" is strong enough plastic but maybe. possibly a narrow pipe that mounts to the floor board up near the front of the foot rest and just goes straight up without getting in the way of anything else? i don't know, just thinking out loud.... i imagine it (they) would have to be off centered to the side to see around the rear fenders.
now if i had an air conditioned heated cab, this would be easy!
amp