Yep, that will work fine. CMD8GX3M4A1600C8 isn't Dominator GT though - if you want GT (i.e. with the red heatsinks to match the mobo) then look for part numbers starting CMG... or CMT... The latter (CMT) supports the DHX Pro connector for the Airflow Pro.
The CMG4GX3M2A2000C8 was built with Elpida Hyper ICs, which wer expensive, but is not made anymore. The CMT4GX3M2A2000C8 is a different IC - not as costly, so therefore better value.
For the absolute highest-performing memory, you'd need to step up to Dominator GTX (which is a step up in price too).