Camera upgrade advice needed before lens purchase!

[lukeshoe1993]

Hi everyone - I come to you in need of some serious help!

I am looking to purchase a new lens to allow me to expand my service portfolio in both videography and photography - As well as for allowing me to make my own films.
I'm currently looking at a few options:
18 - 135mm EF-S IS STM 3.5 - 5.6
24 - 105mm EF IS STM 3.5 - 5.6
24 - 105mm EF IS USM F4 L

My thinking is that the STM will be better for Video as it will allow for smoother auto focusing, but of course the L is an exteamly good lens in itself.

This isn't too bad of a decision on its own. But I am looking to get this lens now to add to my Canon 650D's range and then (When I have the money) I want to use this same lens on my New camera.

The question then becomes - What do I upgrade to?
Canon 7D MK II
Canon 5D MK III
Blackmagic 4K Cinema Camera with EF (used for videography only and would use my 650D for photos)
or a wild card suggestion

The problem with the Blackmagic is that it has poor low light performance as its ISO tops out at 400 (I believe) as well as not working with (most) EF-S. The 5D MKIII is expensive (and slightly outdated) and doesnt work with EF-S. And the 7D MKII has an APS-C sensor and seems to lack some other desirable features.

All however are more than capable of producing stunning images

The decision on the Camera will influence my choice on Lens - I currently have more than enough to purchase any of the lenses above - but of course the lower the price, the more I have for a Camera Body.

So, yes, any help would be more than appreciated - I'm just getting lost with it all!

Cheers,
Luke