Any spell effect can be enchanted into any piece of armor or clothing or any weapon. Armor, clothing, and weapons can all use cast-when-use enchantments, weapons can use cast-when-strike enchantments (though this does not work properly with bows), and everything can use constant effect enchantments if the soul being used is 400 points or more. Golden Saints are the best source of 400 point souls but they don't appear until you get to the higher levels.
So, yes, you can make an item with constant effect spell absorption.