Reginald is good, he'd get Reg or Regie. the Bootlace part concerns me though, kids can be cruel, i cant imagine my son going on stage to get his university diploma and having the MC read out REginald Bootlace though, seems more like a nickname than a name.
Petunia is a sweet name for a girl, like PZ said though it does remind me of harry potter, and im pretty sure her surname is picklebottom, but HP probably wont be as popular once your little one is at school, so it probably wont be an issue