Eliminate vent windows?

Will not work. Different windshield, different A pillar. Wouldn't line up at rear.
Best to forget you even thought of it and move on. Poly carbonate sheet is your
easiest option if you must. Unbreakable. Commonly used in race cars that have
been lightened extensively. Not really a good product to replace automotive glass.
Scratches very easy especially if made to go up and down. And won't stay to shape in a frameless door application. At least not enough to have any kind of a working seal.
But it is done, you wouldn't be the first.
If this is to be a street car that you use you would regret the installation.
Now if you wanted to do it right with tempered safety glass you would have to have a pattern
and send it out to get custom glass made. I would guess and this is a guess around 300.00
up per piece if you could find a place that would even mess with it. They like to do large volume
runs