For the health, use the "Item Life Bonus" ability. Just set it to be a unit ability, and it should be fine.
I searched the natives in Jasscraft, and there seems to be no way to affect an individual unit's damage *and* have it display without making it a bonus.
If making it a bonus: Use one of the "Item Damage Bonus" abilities.
If non bonus (it won't display on the unit's info pane): Make a trigger that, if an attacker has your ability ("item life bonus"), causes it to deal x amount of damage to the attacked unit.