Was able to get my own question answered via the Text Chat with Intel.
It does appear that the DA card is the equivelent of the SR2 card without the optics. Ordering the DA card with SR optics from Intel provides the same spec as the SR2 card.
Snippet from conversation;
Mauricio: Cable lengths for Intel® Ethernet SFP+ Optics
: This is what we are trying to get - 50 µm MMF 2000 2 to 300 (meters)
: So as long as we use this Optic with the DA card we should be within that range on MM fiber.
: SR Opt Trcvr for Intel X520 SFP+ NIC, Customer Install (330-8721)
The card also does not have any known issues with Windows Storage Server 2008.