Just to throw something else out there- have you thought about Graydon? It's similar to Greyson- but different and I find it to be more masculine.
Thank you for the suggestion.
I mentioned to DH that we also consider
Grady Elliot and Graydon Elliot or Grey Elliot (As incorporating the color name Grey/Gray was our original intent.)
Sometimes it feels like we take one step forward and two steps back! But, I know that when he arrives we will choose the perfect name :)