There may be some correlation between solar energy and UV transmittance, but that's not what the measurement is. Solar energy %, is measuring heat transfer through the material. Clear - 85% of the heat transfers through and 2412 only 35% through.

Although, bronze 2412 only lets 25% of the light through - visible light measured at 6500 deg. Kelvin (normal daylight). So it's pretty dark. Might try getting a small piece of film with the same light transmittance (sample from car shop) and seeing if you really want it that dark.

Also, be aware the spec numbers (2000 series) you've given usually refer to plexiglass - in this case Acrylite, not polycarbonate - Lexan. Bronze Lexan usually uses 5000 series numbers. Might be why it is much less expensive than I would expect. Worth looking into/verifying.

Your thickness range is about right, some acrylics (depending on which one you actually end up using) have a bending radius of 100 times their thickness.

Greg