I must say I’m most great full for all response this have propelled my thoughts so much further.
@LukeBeno as you both has pointed to there is much I have left out. So I will explain some more. There is no need to stream the data all data just need to be stored for the last 8 seconds (would work with less but 2-8 would be nice). Then when the system is stopped due to external instruction or internally the system can fetch data from each individual RAM when i’ts needed to inspect what did happen and be able to scroll through. So the buss speed will need to be about 500kbit/s. So the buss will not need to be to fast.
My constraint is:
*Space is a constraint since I would like to fit the complete system in a box which is about 550x450x200mm.
*Signal integrity is of great importance since one the signal switched are measured by other systems.
*Robustness of the system and downstream systems. So the dynamic watch of the current and voltage is to
ensure no damage to the SSR and the connected systems.
*Logging of as much data as possible to ensure no need for rerun to understand why things happened.
Budget…as always that is a factor. 
This is not how I ment as I thought I would use two ICs to drive a driver I would use driver side low and high. So that if both ICs (current and voltage) would agree that all is fine the relay remains open but as soon as one decide that is not ok that IC just switch the pin and the SSR closes.
Great I think that would shave of about 50% of the SSR cost, but that would increase the space need. So many tough decisions.
That one seems perfect. I will look in to using an F3 or F4. 4 ADC at 5Msps is crazy. And The cost would be about 40% lower per Msps but the logistics of using only one Memory would be nice. The only problem I see with that solution is that the largest 3.3V compatible RAM I have seen is only 512Mbit. The higher ones is lower voltage… I could use two and do multidrop on the dress pins and feed two memorychips.