Upload & Sell: On
While I have transitioned over from 5 D II and III to a NEX 7 and couldn't be happier, I am not sure that I would recommend you do the same, Edward.
First off, there are few options for flash and lighting. Then, NEX 7 isn't so great at higher ISOs. I stick to 100. Then you haven't got so many options for wide angle. I love the Touit 12mm, but of course keystoning is acute. The Sony 10-18 is nice enough, but suffers from color shift on the wide end with NEX 7.
Lastly, but that is your call and not mine, if a photographer I paid showed up with a NEX, I am not sure I'd be so happy, as it looks anything but pro.
Oh, there are positives, too. IQ of the NEX 7 leaves that of the 5D III for dead in DR, colors and contrast. And it is small, light and stealthy enough that I never leave home with it and 3 primes, be it to buy bread or to go the end of the world. And, it you have a mind to that, you can use your Canon lenses on it, either with a SpeedBooster or an electronic adapter. You can mount fabulous and stealthy Leica M glass. You can even use it for tilt or shift with an adapter. But I haven't cared to tread these water yet.