Normally, I would agree with the opinion of previous posters who said that too many y’s clutter up a name. Often, that can be true.
BUT, in looking at your combos, I MUCH prefer the repeated y’s!
For some reason, it looks better, in my opinion.
For that reason, I voted for [name_f]Sylvia[/name_f]. 
Also, I would love to see you use [name_f]Sylvia[/name_f] in the first name spot!!
Gorgeous name that deserves to be used more!