I completely forgot to mention that another reason the VIS tops are a big no-no is that there is a giant curved Lexan window at the back, and that's guaranteed to pick up lots of scratches. I would hate to be constantly trying to buff it out. An OEM top is better with its glass window, but they're also 3000 dollars and I have a feeling I can get something very nice and custom made for that kind of money.
It really comes down to the money. A Miata OEM style top can be had for 1000 bucks. Totally worth it, I would work with that and try to optimize it from there. MR2 Spyder tops start at 2k+, which opens up the custom work door.
I'm eyeing a car with a roll bar installed, so I can definitely make a "bikini top" like this
and add a frame to keep it sturdier. However a big reason I hated my old MR2 Spyder is the tremendous wind noise from the soft top which made my ears ring, and I really want a hard top so it is more civilized. Adding a rear window and sealing the door windows to the top is going to be impossible, so the wind will be roaring in my ears as I drive.
It's pretty funny because when I got my FR-S, I was shocked by how quiet and comfortable it was on the freeway, while everyone on ft86club likes to complain about road noise, wind noise, and a harsh ride. If I can get half the noise reduction going from the MR2 to the FR-S, I would be ecstatic.