I came across an Apple iMac Retina 5K 27-inch (2017) for a really good price, how well does linux work?
Specs:

• 4.2GHz Quad-Core Intel Core i7
• Upgraded to 64GB DDR4 RAM
• Radeon Pro 580 8GB Graphics
• 27” Retina 5K Display

Mint works fine on a 2014 Surface Pro 3 with 4gb of memory and a core i3. I’m sure any distro will work fine on what you’re looking at.

I installed Linux on a 2016 iMac Retina 5K 27-inch with the following specs (copy/pasted from the 2016 order email):

• 3.2GHz quad-core Intel Core i5, Turbo Boost up to 3.6GHz
• 8GB 1867MHz DDR3 SDRAM - two 4GB
• 1TB Fusion Drive
• AMD Radeon R9 M390 with 2GB video memory

I upgraded the RAM to 24 GB back in 2016.

My daughter uses it to play Minecraft and some lightweight games on Steam and it doesn't break a sweat. I installed Ubuntu 24.04 and it had no trouble finding drivers for everything.