I don't like
Ophelia, it seems pretentious and hyperliterary, and the "feel ya" sound and the accompanying jokes are a problem. In fact I think they're more of a problem than the Shakespeare connection.
I don't like the spelling
Gillian but I do really like
Jillian. I pronounce Gilian just like
Jillian. As for the nn
Jill, none of the Jillians I met were ever called
Jill, to my knowledge.