I'll probably just play games off the external to save the messing around, and then when Sony announce their compatible SSD's I'll pick up one of those too.I got a western digital 4tb from Amazon years back for £100 or so. They usually on sale every Black Friday, so wait.
https://www.eurogamer.net/amp/digitalfoundry-best-ps4-xbox-one-external-hard-drive
Are you going to play games off the external? Or just store them and move them over? I would recommend storing and moving, so you benefit from the faster loading times.
But wish they had SSD expansion like Xbox at launch.
This seems a good one.
https://www.amazon.co.uk/Seagate-ST...p/B076H6TZ7L/ref=psdc_430544031_t3_B017KE8OG0