I like [name_m]Leo[/name_m] [name_m]Giovanni[/name_m]. The middle balances out the first in terms of length, and I just happen to like [name_m]Giovanni[/name_m].
I like [name_m]Caius[/name_m], [name_u]Phoenix[/name_u], and Josai, but not with [name_m]Leo[/name_m] since it is a bit choppy since both have two syllables.
I suggest [name_m]Leo[/name_m] [name_m]Malachi[/name_m], [name_m]Leo[/name_m] [name_m]Raphael[/name_m], and [name_m]Leo[/name_m] [name_m]Caspian[/name_m].
I like a longer name to balence out [name_m]Leo[/name_m], and [name_m]Leo[/name_m] [name_m]Giovanni[/name_m] is so romantic sounding, so that would be my pick, followed by [name_m]Leo[/name_m] Mikias