User Activity

I'm wanting to compare the sensors between the 5DM4 and 7d, as far as noise. I know the 5DM4 is better, but practically, how much? If I'm shooting the 5D at ISO 800, what would would get me similar results with the 7D? ISO 400? ISO200? Is there a sou...
I want to shoot a series of shots for a time lapse video. I'll be shooting at 1/125 @ f8.0, ISO 200, in LIVE mode, with the interval of 10 seconds. Can someone give me an approximation of how long a freshly charged battery would last? 
I use a 5DM4. I'm looking to get some extra memory cards. Since I shoot a lot of time lapse videos, I need a pretty high read/write speed. I currently use SanDisk Extreme Pro CF card, which writes at 160. I see CF type B cards with transfer rates of ...