Based off your ID will determine what rare will drop on chance, it's pretty a bad choice if you get the wrong ID. If you get the matching ID to your class you will be set for most of your equipment needs.
Virdia: Shots
Greenill: Rifle
Skyly: Sword
Bluefull: Partisan
Purplenum: Mechgun
Pinkal: Wands and Technique Disks
Redria: Armor and Shields
Oran: Daggers
Yellowboze: Higher amounts of meseta all weapons and items drop from this ID. The best bet out of all IDS.
Whitill: Slicer