Well, with
Boyd as the surname (I didn't assume that from your posting name.), I vote for
Graham Mitchell Boyd.
Graham Boyd flows and sounds far better, to my ear, than does
Bruce Boyd, not that
Bruce Boyd is bad. The slightly sticky "m"-"M" transition isn't difficult to say; just makes me pay attention to my lips and, as you point out, it's his first and last name that will be said most of the time.
Maybe when the twins are born, big sister,
Morgan, could have a new male baby doll named
Bruce to mother. :)