I think they're both very classy names. Aubrey is actually one of my faves for a boy.
I'm not very good with mn suggestions, but maybe somethiing ending in -s; or -n for Aubrey and -y for Caspian.
Aubrey Louis
Aubrey Lucas
Aubrey Marcus
Aubrey Camden
Aubrey Duncan
Caspian Louis
Caspian Henry
Caspian Lucas
Caspian Marcus
Caspian Alistair
*laurel* loves Ophelia Margot, Margaret Eloise "Midge", Stellan Aubrey Oswyn, Camden Montgomery