I read these words as if your stated needs are either superficial or coming from GAS rather than real business needs. If you are actually running a professional photo/video business, you should know the moment you start re-thinking of new tools and re-investing in equipment, you lose your income. A real business minded pro gets the job done with whatever tool he/she has rather than complaining on forums. Switching to a different brand/system because of record data rate is laughable at best. Get a few more dirt cheap HDDs or SSDs and get over it. If your customers are not satisfied with the quality of your work, perhaps tools play a minor role in that. If you yourself are not satisfied with the quality of your work, there are other avenues to investigate and re-investing in tools may not be the only or the best decision.
Anyway, back to the question of what cannon offers for 4K production:
For 4K production, C200 up. It meets the production needs without any gimmicks. And for FHD, as you mentioned you are comfortable with, again C100 gets the job done without any flaws. Moreover, both systems are scalable as the needs and business grow.
If these do not satisfy your needs (both quality and budget), better look elsewhere. wasting time on forums will not help.
Ok, first of all: why the hell would changing to new tools mean a loss in income??? Belive it or not, we can afford to by a second set of cameras and sell the old ones on a later date, once we established a working an reliable workflow.
Now to the "GAS" and your "a working pro gets the job done with whatever tool he has": okay, please tell me exactly how we can produce a better image in our studio with the 5d iv and 1dx ii without switching to 4k? I compared other "tools" 1:1 side by side with the 1dx ii in fullhd and guess what, the sony a7r iii and the sony gh5 both produced a MUCH better fullhd image at the same setup. Its just a disgusting compression on the canons fullhd image, that cant be removed with any smart professional skills you may offer. And its not that the client is realy unhappy, but its 2019 and I think more and more, that this image quality is not up to date and would raise an eyebrow, If we didnt improved it by 2020.
As I said, "a few more" HDDs wont handle that. Currently we film up to 4 days per week, 8 hours straight - if we would switch to 4k (the ONLY better setting the canons offer) we would result thanks to the idiotic MJPG Codec at over 6tb of files per day that we need to copy on a server, upload and distribute on different workstations. This is an insane amount of time and a total unecessary amount of money we would waste. I would pay 800$ per week just to get new harddrives.
The situation is this: I am a photographer but right now we happen to produce more videos. I do NOT want to buy 2 new ADDITIONAL cameras (actualy better 3, as we should have one backup). I just want a decent all around workhorse.
If Canon just put a usefull 4k in their flagship DSLRs, then everything would be fine.
I REALY doubt that my niche is very small or special: "
Photographer that also make 4k videos and want a decent all in one tool". It wouldnt even matter if it was 6000$ like the 1dx II (which is a overprized and VERY specific tool), since one would need only 2, not 4 cameras. They could have just released ONE workhorse for EVERYTHING, by just implement a decent 4k mode in the 5d IV. That would have made A LOT of people happy. But they choose not to, and they did so again with the (clearly consumer focused) EOS R.
But you are right with one thing though, I am wasting my time here.