PoE Texas Raspberry 3 B+ and 4 Pi Hat Accessories (GAF-PiHAT-FBA)

This listing shows 3 enclosures - what are the amazon listing codes ( asin ) for each of them? anyone know?

Im looking to use your hat to power some pi3s with the official 7 inch screen. i can pull power from other pins, but are you using the i2c pins?

how to install fan when poe hat takes one of the pins to do so?

If pi 4 has gpu heat sink will this board work?