Looking at the 2019 lineup of 27-inch iMacs, wondering which will best serve my needs. My main use is for Photoshop, sometimes working with large files of 100 layers or so, up to 2-3 GB. I do absolutely no gaming nor video processing. I use external drives for my main storage and only use the internal drive for the OS/Applications and current work. I’m looking at buying the base model 3.0GHz i5/8GB iMac and then bumping the RAM up. As I’m only working with stills, it seems that should be plenty good enough spec for what I need. I see many suggestions on various threads (mainly people processing video or gaming) that upgrading to an internal SSD rather than Fusion drive will help speed things up. Given that I don't do video or gaming, and that the fusion drive already has an SSD component, would this be enough? Would an internal SSD actually make a noticeable difference for my usage? I already have an external 500GB SSD, so would using this achieve basically the same benefit (if any) as an internal? Any suggestions would be much appreciated. Thanks in advance.