Table: Random Magic Item Generation
Minor | |Medium| |Major| |Item
01—04 | |01-10| |01-10| |Armor and shields
05—09 | |11-20| |11-20| |Weapons
10—44 | |21-30| |21-25| |Potions
45—46 | |31-40| |26-35| |Rings
———— | |41-50| |36-45| |Rods
47—81 | |51-65| |46-55| |Scrolls
———— | |66-68| |56-75| |Staffs
82—91 | |69-83| |76-80| |Wands
92-100 | |84-100| |81-100| |Wondrous items

just a 1d100 table from d20srd. should try to stay close to that? possibly?