I'd like a Rappy Minion too and some of their ARKS starting outfits.

But considering how they get Odin trial and also relic items -> http://i.imgur.com/5WltW9E.jpg I think FF14 should also get weapon rewards from them too (I don't think there would be a collab trial for Dark Falz, only a FATE at most)

For weapon, I imagine they could give the following matching weapons to the current respective jobs in this game.
PLD gets Gunslash
WAR could get Double Saber
DRK gets Sword
MNK gets Knuckles
DRG gets Partizan
NIN gets Twin Daggers
BRD gets Bow
MCH gets Assault Rifle
BLM gets Rod
WHM gets Wand
AST could get Talisman or at least remodeled from that weapon
SMN/SCH might get a spellbook with Rappy design on it.