Possible enchantments are as follows:
It is worth noting that staffs with Destruction enchantments are not uncommon, and can often be found on Liches and other spellcaster enemies, so despite its convienience, you would probably be better choosing another enchantment. Particularly recommended would be Paralysis, since spells or poisons which cause Paralysis are quite rare and expensive. Furthermore, Paralysis cannot be applied to weapons at Altars of Enchanting, so this may be your only chance to obtain a weapon with that feature. Charm and Dispel would be a waste of your staff, since they are of limited utility, and quite inexpensive anyway.