Ya, now that we're saving money on a camera that shoots film-look, let's now add a few thousand dollars more for a mount...I mean...it's only fair right? We can't have our cake and eat it too, you know!.
Funny you mention that, there are iris rod mounts for DSLR that when fully laid out more than double the cost of a 5d mkII. And that is with a fairly lame follow focus like the Red Rock one. The numbers with a proper Chrozeil (sp?) are just nutty.
Basically if you go all accessory crazy, you're paying about the same as the buy-in on an HVX-200a new, or a used HVX package with goodies.
Here's a short film I did last month, testing the camera out in a narrative production environment with lights, crew, etc.
http://vimeo.com/8145618
Very nice. Timely story too.
RE: In-camera audio vs. external recorders.
If the external is in the budget I would go that way almost every time. Some cameras do a pretty good job of munging your audio signal by comparison to a dedicated recorder, and I'd imagine on a 7D or a 5D-II where you need a box between the xlr and the camera the problem might be exacerbated enough that an inexpensive recorder is a viable option.
The flip side is a more robust video camera may be a better audio recording device than a budget digital audio recorder. It just depends on the gear.
Sync in the world of digital NLE isn't that big of a deal, even without the benefit of locked time-code between the recorder and the camera. There's where it gets prohibitively expensive for the no-budget crowd. It is extra work in post, but not terribly hard especially on short pieces.
Bottom line though, if you can afford it, get an on-set recordist that can boom AND monitor levels. Even better, a dedicate boom op and a recordist. The difference is well worth it.
