High quality Nema Twistlock receptacle for Hydra

I am about to have a power cord customized for my Shunyata Hydra. I was wondering whether anyone knew which would be the best receptacle to use on that cable (the plug is on the Hydra).
I only know about the Marinco, see for example Marinco Nema L6-15, which also seems to be the one on the Shunyata Sidewinder that came with my used Hydra.
Thanks for any advice.