Possible weapon properties I am refering to would be,
Druid Equaliser Staff
Regeneration.
Charges of Prot. Alignment and Natures Balance.
Attack bonus vs Chaos and Law.
Assorted bonus spells appropriate to item level.
Assorted damage bonuses appropriate to item level.
Cleric Staff of Contrition
Regeneration.
Charges of Searing Light and Sunburst.
Attack bonus vs Undead.
Assorted bonus spells appropriate to item level.
Assorted damage bonuses appropriate to item level.
Bard Spellsingers Staff (mid to high 20s due to feat bonus)
Regeneration.
Charges of Deafening Clang and Great Thunderclap.
Bonus Feat : Automatic Quicken Spell I
Assorted bonus spells appropriate to item level.
Assorted damage bonuses appropriate to item level.
Just some very rough notes there but you get the idea. A few magic staves for the "other casters" would be great.