Stephen is not one of my favorites, but I think
Stephen Alexander is a good combo. It flows well, and it "booms" in a commanding sort of way. Sounds royal.
I prefer
Nathan, though. It's very sweet and low-key and I love Nate/Nat. I don't know if you like any NN's, but whatever. I would use
Nathan in a heartbeat.
"An intellectual says a simple thing in a hard way. An artist says a hard thing in a simple way." -
Charles Bukowski