"I don't know ANYONE that shoots anything serious on a 6D."
Thats kind of the point. The 6D was a joke for video, largely because of the codec, which made even the 1080 it had pretty useless. There was a chance to bring the 6DII out, 5 years later, as something more. Instead they seem to be using a very similar codec and just added 60fps. Not exactly progress.
Didnt even notice the lack of headphone jack, thats definitely embarassing seeing as they have it implemented in many other cameras. And the body size grew from the 6D, so its not like it was space saving.
Im guessing they think that the market that wants those features, but not a dedicated cine cam like a C200, is small enough they can piss them off. In the meantime, Ill be using my a7r because its better for stills, and my GH4 because it does video. Thought the 6dII would be how Id go back to Canon, but, if anything I see myself moving all Sony once they fill out their lens line in another year or two.
If you dont need the 4k but like the idea of the GH4...and want a filmic look, then perhaps the GH3 and a Metabones adapter is what you are looking for? The combo would get you plenty shallow depth of field, and price wise it'd still be cheaper than just a GH4 alone.
No matter what, avoid DV...what a nightmare that process is.
Are you adapting the Tokina 11-16mm to m4/3? Or do you have the cine version?
I ask because if you're adapting them with something like a speedbooster, then I'd just get the Sigma 18-35 in whatever mount you are using. You get better low-light, and in combo with your Tokina, you cover the range.
If your lenses are all micro-four thirds however, then I'd say your bought into the mount, so the 12-35 would be a decent purchase.
Since you'll be using vintage primes, there's really no reason to go with the 700D. Get a T3i instead, save yourself a few hundred bucks, and spend it on lenses instead. The 700D and 600D use the same sensor and have most of the same specs...for video, you wont notice a difference. In photos, you'd need to be using auto-focus lenses to notice a difference, and even then, it'd be a small one (f/2.8 lenses or better would be noticeable with dual-cross points).
You can spend $3-400 on the body and the rest on lenses and kit, rather than $6-700 on the body.
You should get an external drive because right now, you are a hard drive crash or software glitch away from losing your entire short, it would appear.
Guy's suggestions are great, though I would reccomend getting a couple of 3TB drives over a single 6GB drive. Allows you to keep multiple backups over time, and leave specific drives to certain projects. For example, I am using 2 separate 3TB drives right now...the first is dedicated to my documentary project (using about 500GB of it) and the 2nd is an archive of all my video and photos shot (using about 2TB of it). When the archive drive gets close to full, I'll buy another drive (perhaps 4 or 6TB) once a new project starts, and keep using the other two as archives. Rinse and repeat.
If this work was for a paid client rather than myself, I'd also be backing it up online and probably keeping a duplicate hard-drive in another location