I stand corrected, there was a MSA2070s in the plans. Any reference to this is gone from all HP partnumber databases as far as have been able to determine.
I found some information about the MSA2070s and MSA2060s being scheduled to be introduced end 2007. Guess that never happened.
I've never heard of these models, and I like to think I know most of the HP storage products out there. Perhaps you've gotten hold of some very limited release, or perhaps even a pre-production unit.
Since this was planned as a replacement for the MSA1000/1500, it will have a built in RAID controller. The 4 SAS ports is also an indication of that. Therefore, a P800 card will likely not work since that card has onboard RAID.
The SC44Ge also seems to have some form of basic raid, it's supported to attach to the MSA60 and 70 (and perhaps others) dumb drive enclosures.
The supported HBA to attach to an MSA2000sa (SAS version) is the SC08Ge 488765-B21. This would be your best bed, but there are certainly no guarantees. You may not want to spend on a card to attach to a completely unsupported disk array.