My favorite for you is Edmund.
I think [name_m]Edmund[/name_m] [name_u]Zephyr[/name_u] [name_m]John[/name_m] sounds great 
[name_f]Iris[/name_f] & [name_m]Edmund[/name_m] are lovely together! Maybe keep [name_m]John[/name_m] in the middle? It would make sense, especially since [name_f]Iris[/name_f] has two middles.
[name_m]How[/name_m] about [name_m]Edwin[/name_m] [name_m]Theodore[/name_m] [name_u]Zephyr[/name_u]? I think it flows really nicely and works well with [name_f]Iris[/name_f] [name_f]Isobel[/name_f] [name_f]Xanthe[/name_f]
I think [name_f]Iris[/name_f] & [name_m]Edwin[/name_m] are great! If you feel that strongly, don’t let the family get to you, drop the [name_m]John[/name_m].
Or some T names, for [name_u]Teddy[/name_u]…
[name_m]Tadeo[/name_m]
[name_m]Tage[/name_m]
[name_u]Tait[/name_u]/[name_u]Tate[/name_u]
[name_f]Taren[/name_f]
Tavin
[name_m]Teague[/name_m]/[name_u]Teagan[/name_u]
[name_m]Thad[/name_m]
[name_m]Thorne[/name_m]
[name_u]Tobin[/name_u]
[name_u]Trace[/name_u]
[name_m]Trent[/name_m]
[name_u]Tristan[/name_u]
Thank you all very much! We think we’re going to go with [name_m]Edmund[/name_m] or [name_m]Edwin[/name_m], but we want to be sure so are going to start trying them both our soon. We still haven’t decided whether or not to keep [name_m]John[/name_m], I want to nix it completely but I know it will hurt my former step mum when she finds out. My partner likes the suggestion of swapping it out for [name_m]Jack[/name_m] or [name_m]Ian[/name_m].