Before any decision is made I think you need to be honest with yourselves about how and where you are going to live - if you are going to live in England then the boy needs an English/Welsh name that might play well in France. If you're going to live in France he needs a French name that nods a little bit to the Pays Du Galle.
Growing up in England with a name like "Blaise" would be a nightmare for a boy.
"Max" is not a name - it's a abbreviation of Maximilian and being given an abbreviated name like "Tony" or "Mike" is not a good start for a kid let's be honest...
And... hang on a minute - a half French, half Italian guy hooks up with a Welsh girl and then wants to dictate a name that works well in English and French ??? Where's the Welsh ? Where's his respect for your heritage ? And where's the Italian? And where is his head if he thinks he can make a big fuss about his national heritage while ignoring yours - and this baby's ?
Where will this boy grow up and go to school?
Will his Father teach him French and Italian from day one (and throughout his early life)? Is there family to consider ? Or is it just macho stuff of the father wanting the son to reflect him from day one?
Let me tell you that Blaise would be a VERY, VERY tricky name for a boy to go through school with in England...
Montgomery is the obvious name to please all parties - a place in France, a place in Wales and a fine old traditional name in England.
(and by the way, living with the name Monty has been pretty good..)
Otherwise...
Morgan (trad' Welsh name and famous French rugby player)
Hugo
Zak (no-one on earth can mispronounce it) but must be christened Zachary or Zachariah so he has the choice later in life...
Theo
Xavier
Aled
Bryn
Marc
Gwilym (or Guillaume) or make up a compromised spelling... One of the oldest names in Both Welsh and French.
and if you're feeling a bit Stone Henge and spiritual - Emrys - sounds GREAT in a French accent.