Sound Solution for the Canon EOS 5D MkII

I've been discussing with film-making friends today, the possibilities of recording a short film using the Canon EOS 5D MKII. Of course, alarm bells for me ring when considering how to record sound with the camera being as it is a stills camera. It can record onboard sound and has a 3.5mm jack input for connecting an external mic or break out box, but the camera offers no gain control and so would add auto gain to your incoming audio - not good! A bit of internet research led me to this video - which ironically has slightly ropey sound - but is no less a great tutorial on using an external device such as the Zoom H4N with the camera. I would be looking to employ my Fostex FR2-LE with the camera if possible, but I guess you would just substitute the Zoom out for that.

Advanced Sound for DSLR's from Steve Weiss, Zacuto USA on Vimeo.