NEW mac's

I think the M1 Mac Mini might be the best option but as of now Premeire Pro will not tap into the M1 chip 100%. The M1 chip is still in a trial and error phase. Could you wait another 6 months and see what the M1X chip has to offer over an Intel chip? 

Your choices are limited and in flux due to Apple's transition from Intel to the Apple silicon architecture. You absolutely do not want the 21.5" iMac non-Retina at this point as it has not been updated at all in the past four-plus years (the currently-still-available model dates all the way back to 2017, and it does not use even a desktop CPU but a low-power dual-core 7th-Gen mobile Intel CPU that's totally inadequate for media content creation). And since the 27" iMac models are outgoing as well as being too expensive for school use, this leaves only the 24" iMac. Skip the base 24" model configuration as it has an insufficient number of external USB connectors (only two Thunderbolt 4/USB 4 ports total) and no wired networking capability whatsoever (no Ethernet port, only wi-fi).

I eliminated the MacBook and the Mac Mini models due to their very limited connectivity options, and the Mac Mini requires the purchase of a separate display monitor for each system.

Moved to hardware forum.