I am thinking of buying the Ronin Essential KIt.

I have a Sony A7s 2 and a Canon 5D 2 - which cables do i need for the ronin s?

How much control will I get?

Hi martinsthomas, sorry for the late response and thanks for your interest in Ronin-S. For Sony A7S 2, RSS-IR and MCC-Multi cable both can be used, please check the compatible list to see which cable you would like to purchase: https://dl.djicdn.com/downloads/Ronin-S/20190314/Ronin_S_Camera_Compatibility_List_en_.pdf
Canon 5D 2 is not in the compatible list, the compatibility cannot be ensured and we do not have the cable can be recommended, sorry for the inconvenience. Hope other users who have the same camera can give some advice.