What a choice to have to make! If it was me, I would probably keep the 411G (it's a great, versatile machine) and the Grasshopper (cute and portable). I would get rid of the 221 (strong resale value, and not needed if you have the Grasshopper), and the 128 (Grandma indoctrinated me against long-bobbin machines). Then it gets harder to decide... I would probably choose the third based on looks, so I would probably keep the 201, but either the Brother Tingler or one of the clones would make more sense for most people on that basis. I just really like the look of the 201.
I'm looking for a treadle for the same reason - power outages. Unfortunately, long-bobbin machines were popular on the prairies much later than in the rest of the world, so it's hard to find a round-bobbin treadle. The search is part of the fun, though!