According to personal research, along with your advice, I find this to be the ultimate Junction setup:

HP: Meteor
Str: Aura
Vit: Meltdown
Mag: Flare
Spr: Reflect
Spd: Triple
Eva%: Stop
Hit%: Double
Luck: Death

Elem-Atk: *depends on circumstances*
Elem-Def: Ultima/Life/Full-Life/Shell

St-Atk: *depends on circumstances*
St-Def: Esuna/Pain/Sleep/Confuse

Please note that this is from the top of my head, so some info might seem rather queer; but I still think this is a decent setup.