Is this for the 65 gal in your signature?
If So, I'd say 620's will be a bit underpowered.
I'd go with at least a pair of Seio 1100's possibly even 1500's.
If you go with Hydor Koralia's, a pair of K3 or K4's would do the trick as well.
Softies like a lot more water flow than most give them credit for, and unless your LPS are super fleshy types, they won't mind the flow either.