These look great --- I love the way it looks on silver above and I like the medallion size as well.
I'm indifferent on the different coin faces as I actually love the one you've already modeled.
The idea of gifting one to the foundation and another to the millionth block staker is perfect, I think. I would also be very interested in purchasing one if possible.
I think a lot of people are excited to purchase one so I think they will have to make that an option.