The only way I recommend you put a proc on your weapon like the one shown above is if you're playing a race that's immune or highly resistant to that type of damage. Weapon procs like the one shown above generally are not worth getting in Morrowind because many high level enemies come with spell reflect. Of course there will be some enchants that I missed and never made it onto this list. Keep in mind that this list is biased and only includes custom enchants that I personally came up with or that I read about online and made myself. This page contains a list of the best custom enchants that you can make in Morrowind with the Enchant skill.
List of all the Custom Enchants I made - Elder Scrolls: Morrowind