This sounds like you want what the pros use. The RED has such systems. There may be other pro systems that do this but 100 megabit? That isn't done for many reasons in consumer gear. Mostly because the gear to do all this is expensive, consumers balk at the setup and other reasons.
The Red page is over at https://www.red.com/
Is there a solution to use a big HDD instead of a small sd card in a camcorder (why makes Sony etc. noch possible to use a HDD at USB port?!?)?
A intelligentent adapter from SD slot (with dummy sd card with cable) to usb plug, or a sd wifi card that send the data (max. 100Mbit/s) live over wifi.