Those geta look horribly uncomfortable. I'm sure I'd fall off and break my ankle if I tried to walk in them!

The flip-flops you linked to don't look very cushiony, actually. All the flip-flops I've ever seen look soft but actually have no give to speak of. (But then again I only look at cheap ones, so maybe good ones are softer?) I don't think the platform flip-flops would be any softer than the normal ones.

crazyladynocats's idea of cutting a hole in a soft insole sound like a good one. They make heel pads with holes in them for heel spurs ... why not full-length pads with holes in them for forefoot pain?! You can't cut up gel insoles, but buy a pair of good-quality thick foam ones, and cut a hole in the appropriate place. You can make the hole as big as it needs to be as long as there's a little bit along each edge to connect the front and back to keep them in place. Why not try a $20 fix before you go for the $200 fix!