I think the baby will be a boy since the latest additions to the Grimaldi Family have both been boys (Sasha and Raphael), although personally I'd like it to be a girl. Some name suggestions:
Girls
Antoinette Honorine* Athénaïs* Marie
Florestine* Aurelia Charlene Caroline
Grace Ghislaine Marguerite Lynette
Boys
Florestan Albert Charles Rainier
Louis Jacques* Michael Honoré
Joseph Louis Albert Pierre
* = Princess Honorine, Marchioness of La Tour du Pin.
* = Princess Athénaïs, Marchioness of Louvois.
* = Princess Florestine, Duchess of Urach.
* = Prince Jacques I.
A little Prince Florestan or Prince Honore would be lovely.
But Albert with a little princess would be adorable!
I agree on Florestan, it's such a handsome name! I remember guessing it for Raphael or Sasha, but that didn't happen. I think it and other forgotten about historical names should make a come back, especially if Albert and Charlene have a girl, because there were a lot of beautiful names amongst the Monegasque Princesses.
I'm not sure about the godparents, but perhaps one of the Casiraghis, Caroline, Stephanie or one of the relatives of Princess Grace, although I'm not sure how close they are to her family.