I think that [name_m]Rafferty[/name_m] is really cool, & I especially love it for the sleek, sporty, dashing nn of [name_u]Rafe[/name_u]. It’s unique w/out being weird, which is always a good place to be. [name_u]Umber[/name_u] is not my cup of tea, but I guess that [name_m]Rafferty[/name_m] Umbert sounds okay.
As a brother to [name_m]Rafferty[/name_m], what about…
Hope this helps.