Thanks very much to all. I think in time I'll see what Overclockers have on offer, but at least I now know it will run at a reasonable resolution. Even so I'll probably be crap at it like most games....
Interestingly, I tried to update the nVidia drivers through its control panel and got some stupid message about not being able to do it. What I might do is wait for the Mac version, as I've got a top notch MacBook Pro retina i7 with SSD, 16Gb and a 2Gb card. ED should run at top res on that.
Thanks again to all.
Kryten