Re: I work in PAL conversions
>Can anyone who does serious work in this area give us an idea of how much storage they need and of what form/location?
Short answer: Shitloads. Redundantly stored on external servers. Thunderbolt to the MacPro for editing.
My friend runs a video production company. Filmed footage is irreplaceable ( you can't return to your client and ask them to re-enact what you filmed in the first place), so all data is redundantly backed up as soon as possible - ideally as it is being shot, or at least whilst still on site.
Thunderbolt is happily fast enough to shunt it onto the editing Mac as required. There really isn't a need for large internal storage.