Im not a DSLR guy (in fact the one and only project I had to do with one made me swear to never stray from a "real" video or film camera again)... but I can speak a bit to a couple of pieces of the ancillary equipment.
For focusing, you can't beat the follow-focus unit from RedrockMicro. You'll find tons of follow-focus units on eBay made in China and India that look almost exactly like them and are only a couple hundred bucks... but most of them are pieces of junk. There's just way too much slop in their gearboxes for them to be accurate (or even usable), which will be especially important when shooting with a DSLR since the SLR lens focus rings are so incredibly touchy. A cinematographer buddy of mine calls them "Fisher-Price Follow Focus" units. The Redrock FF unit is the only one I've seen/used that approaches the quality of an Arri or Chroisel FF unit (which will be in the $2-3K range), and it's a lot less expensive... well under a grand.
For microphones, we absolutely live and die by the Sennheiser MKH416. It's been one of the best investments we have ever made. It's a highly directional shotgun, and really sounds great. It has a very warm, open sound... you'll hear it used on a lot of feature films. Now, it does require phantom power to operate, which of course the 5D doesn't output... but I'm guessing that like most DSLR guys you will be shooting double system sound... so if you use something like a Zoom recorder for audio, most of them do output 48v phantom power so it works just great with them. The mic is not cheap, but worth every penny.
Fantastic Plastic Entertainment, Inc. fantasticplastic.com
Thanks for the input, Todd. It's funny that you've sworn off DSLRs after using them. I'm trying to make sense of using DSLRs but hate how you have to tack on all the other things (an extra recorder because there is no phantom power? Yeesh.) to make it work. Not easy for a one-man show.
I'm also thinking about the NEX-FS100U but I'm not a huge fan of the overall design. Looks a bit clunky. Have you used this camera before?