Buy the i7, the GPU can be upgrade by Thunderbolt 3 Docks later!I'm planning to get the mid range iMac but I was wondering what it's going to be a better upgrade: taking the i7 upgrade on the mid range iMac or going to the high end iMac with the i5 but with the Radeon Pro 580.
Honestly, I don't use my iMac for gaming but I keep running Photoshop all the time so a better GPU might be better than a better CPU? .... I've got no idea, to be honest.
https://developer.apple.com/development-kit/external-graphics/