even when they are spelled the same, they will be pronounced slightly differently. the Normans were French and they brought a lot of French names with them into England and later the Huguenots fleeing religious persecution in France brought more names into England with them.
example: the English surname "Beauchamp" is pronounced "Beachem" and not the French "Bow shom"
below are a few that you may be able to use:
Guy. but it won't be pronounced the same. French: ghee (g is pronounced like the g in goat and the name rhymes w/ key) English: guy rhymes w/ eye.
Alphonse
Alvin
Avery
Brian (different meaning and pronunciation)
Brice
Bruce
Chandler (different pronunciation--sh instead of ch)
Claude (different pronunciation)
Elliot
Gervais (pronounced differently English pronounce it as Jarvis)
Gilles (English: Jiles)
Horace
Hubert (French: U bear English: Hew Bert)
Lance
Louis (French: Loo ee English: Loo iss)
Maurice (French: Maw reece English: Morris)