Need to replace my aging Sandy Bridge i7 machine I built in 2011. After good experience with my MacBook Pro Retina (2.3 GHz i7, 16 GB, 500 SSD + external 1TB LaCie) looking to move fully to Mac for the desktop. Technically, will be two purchases but wife's is easy with either a stock i5, 2 TB Fusion, or since replaced her monitor 2 months ago, could even get by with a stock mini despite it's performance compromises. I am the difficult one. Not a gamer, but a professional photographer who is getting into video. That is also why I built a gaming level machine in 2011 and didn't have the video demand. Base video will be 4k footage from a Sony a7rII. Know I would have to order a custom iMac, went to the Apple Store last evening and my eyes began glazing over when they started talking about and external thunderbolt SSD which research today shows very rare (nonexistent on Apple Site and poor reviews on Newegg). With all options, base RAM as will upgrade aftermarket Probably the biggest question I have when working with video is how will using a thunderbolt external drive as a working drive (not storage)with primary file location vs all on internal drive and transfer to external after project/video is complete. More of a workflow issue Option 1 Stock 3.3 i5, 2 TB. Option 2 Upgrade stock to 4.0 i7, retaining the 2 TB Fusion Option 3 4.0 i7 (or retain the 3.3 i5), 256k (no cost upgrade for 2 TB) + at least 2 TB thunderbolt external Option 4 4.0 i7 (or retain the 3.3 i5), 500k SSD (process video on SSD then transfer files out) + at least 2 TB thunderbolt external. In terms of GPU, thinking of staying with the stock R9 M395 - 2GB rather than upgrading to the 4GB version. In terms of the external, ruled out SSD, but kind of on the fence between the G-Tech G-Drive Pro and the less expensive with more capacity G-Raid.