[name_f]Vivienne[/name_f] and [name_m]William[/name_m] sound a bit to rhymey for me so I would go with [name_m]James[/name_m], even though I love both names!
[name_m]Loving[/name_m] [name_m]James[/name_m] [name_m]Oscar[/name_m] especially 
[name_m]Other[/name_m] ideas:
[name_m]Frederick[/name_m] ‘Fred’, ‘Freddy’
[name_m]Theodore[/name_m] ‘Theo’, ‘Teddy’
[name_m]Albert[/name_m] ‘Albie’, ‘Bertie’
[name_m]Thomas[/name_m] ‘Tommy’ ‘Tom’