What would a brother for Felix be called?

[orchidnap]

As title really! Felix was the only name one of us didn't veto, so really stuck on what another boy would be named.

Middle name would be David.

Help :)

The only Felix I know has a brother called Solly. I think it might be Solomon in full but not sure.

Gregor
Torin
Byron
Seth
Robin

Ooh and
Linus

Alexander