I like the suggestions of [name_u]Callum[/name_u] and [name_m]Calvin[/name_m]!
Also suggest- [name_m]Harrison[/name_m], [name_u]Nolan[/name_u], [name_u]Evan[/name_u]
[name_m]Adam[/name_m] feels too close to [name_m]Alan[/name_m] but I think [name_u]Owen[/name_u] could work.
I enjoy this style. I have [name_m]Alan[/name_m], [name_m]Colin[/name_m] and [name_m]Adam[/name_m] on my list too. Perhaps you would like others from my list:
I think [name_u]Owen[/name_u] works well! it doesn’t feel overly similar but still has a similar vibe to it.
[name_m]Alan[/name_m] and [name_m]Colton[/name_m]
[name_m]Alan[/name_m] and [name_m]Weston[/name_m]
[name_m]Alan[/name_m] and [name_m]Vincent[/name_m]
[name_m]Alan[/name_m] and [name_m]Zane[/name_m]
[name_m]Alan[/name_m] and [name_u]Percy[/name_u]
[name_m]Alan[/name_m] and [name_u]Jude[/name_u]
[name_m]Alan[/name_m] and [name_m]Hugo[/name_m]
[name_m]Alan[/name_m] and [name_m]Ethan[/name_m]
[name_m]Alan[/name_m] and [name_m]Hank[/name_m]
[name_m]Alan[/name_m] and [name_m]Casper[/name_m]
[name_m]Alan[/name_m] and [name_u]Jack[/name_u]