It's my dream job, i would play it like crazy.
Considering that "gunblade" name is currently taken, they can use FFXIII gunblades and just name them "saber" (as in FFXIII). Just add to lore that Garleans designed more advanced version of basic gunblade.
I would hope for more hybrid gameplay, where you can choose something like melee and ranged stance, but i wouldn't mind if they choose cheap design and make "opposite red mage".