Well, people apparently perceive
Quinn as unisex; it isn't used at all where I live, so my only association is with The Mighty
Quinn, which is a marvellous song but, like
Clementine, would get progressively less marvellous the more often it was used. I find
Quinn rather insubstantial, but as I say, I've got nothing to base that on really.
Ellis sounds like a dialectal pronunciation of
Alice, which would be inconvenient for a boy.
Which leaves us with
Rowan! I like it very much and have good memories of the only
Rowan I've ever known, for what that's worth.