I don't know if you have enough material there for both of them to be standalone movies. You could probably have an entire movie focused on New Orleans and the Guilds but I think the Genevieve story probably needs to be part of some larger story. It's not a love story but essentially a story of a con man getting someone to fall in love with him in order to steal from her all ending in her death. We don't care all that much in the comics because we barely knew Genevieve and she is simply a plot device to move Gambit's character along but in a movie devoted to this story where the character of Genevieve gets a lot of screen time, I think it would turn off audiences.
I think Julian and Candra and Guilds must be villains in first movie. Sinister only to appear as Essex and should stay in shadows. No marauders.
Then in second movie let Gambit to join X-Men.
MM and marauders must be a secret. Sabretooth in mansion who knows secrets tells Rogue in flashbacks about Genevieve.
Genevieve story is only to build tention to Gambit/Rogue. Fights Sinister at the end with X-Men. MM and Marauders secrets revelead.
Left to die in Antarctica or changed to smth more logical but Remy won't stay with X-Men.
In third origin is revealed. He unites Guilds and fights someone like New Sun but not from alt reality Gambit.
Team X movies in future or X-Force between solos.