After much searching and consternation I decided to go with old Miata seats on my build. They are comfortable, easy to get new skins for, and (I think) look good. I was lucky enough to find a set for $150 on FB Marketplace, so I picked them up and decided to see how they fit. Long story short: they are pretty close. They are slightly too wide in the back, and slightly too tall in the seat for me (who is 6′ tall), but otherwise I was happy enough to think I could modify them.
With the plastic side covers removed, you can see they are a little too wide on the back. I just trimmed one corner and modified the spring/recline handle to facilitate this.
In addition I needed to make them a few inches lower to get a good height. To do this, I decided to forgo the sliders and remove some of the bucket on the bottom. This works out well for me as there is barely any adjustability in the sliders anyway, and I don’t see the 2″ it would be adjustable making a difference to anyone driving. I tried to show how much headroom I have after this modification, but it looks like right at 4″ which is more than good enough for me at 6′ tall, even if I put on a helmet.
After these modifications I have a good driving position looking directly through the middle of the windshield, a somewhat comfortable leg position (these cars weren’t made to be roomy), and a much more comfortable seat overall. I’ll need to make a better outside cover, but when I’m done with this and reskin the seat, it should look like a new car!