Excuse my late answer, thought I posted my answer Long ago...
My Suggestion for the stat modifier is the following:
•Knight Cloak = Con +1/2
•Archer Cloak = DEX +1/2
•Enchanter Cloak = MEN +1/2
•Healer Cloak= WIT +/2
•Rogue Cloak= DEX +1/2
•Warrior Cloak = STR +1/2
•Summoner Cloak = WIT +/2
•Wizard Cloak = INT +1/2
When adding those stat modifiers I would remove ALL cloaks currently in Possession of Players to make it fair. Then Change the chances to get them since its now pretty easy to get one. Some Player have several of them.