21.5" iMac (4K Retina) for video editing?
I'm seriously considering purchasing the 21.5" iMac (4K Retina), with these specs: 3.0GHz quad core Intel i5 processor, 8GB DDR4 RAM, 1 TB hard drive, Radeon Pro 555 with 2GB video memory. It's main use, other than everyday personal use, would be video editing. We shoot multi-angle, in 4K, and edit on Adobe Premiere, off of an external drive. So would the specs of this iMac be sufficient for this type of video editing, or should I upgrade to the i7 processor and 16GB of RAM, or just go all in and get the base model 27" 5K iMac (3.4 GHz quad core Intel i5 procesor, 8GB DDR4 RAM, 1 TB Fusion Drive, Radeon Pro 570 with 4GB video memory? I don't want to spend more money than I have to, but I'm willing to if that's what it takes.
P.S - as said previously, all editing would be done off of an external drive.