Which NAS for a church for video recording, editing, and file sharing?

[Gene]

I want to move our church from Windows Server 2012 to a NAS. We have less than 1 TB of private and shared office files being backed up to a 3 TB external HDD. We also have a Mac (not connected to the server) for recording our services and for video editing. There are 7 HDDs connected to it with 36 TB of video files. There is a 14 TB HDD connected to it to which I have backed up most of the Final Cut Pro 10 libraries as a stopgap measure. I also subscribed to Backblaze to back up this Mac online. Every Sunday we record our services and live stream them through the Mac. The recordings are saved to the external HDDs until they are edited and published. We need a connection that is fast for the recording and passing of the files to the live stream box, and then need all this data stored and backed up. We also need file sharing, and the ability to connect from any computer, tablet or phone, from anywhere. What Synology NAS do you recommend, how much storage, and RAID 5, 6, or SHR? Thanks.