I like how classic PK is on a level playing field for all and it'd be a real shame if it changed. The classic admins have stated this several times on this forum and aren't going to listen to these wild ideas.
If combat improvements were to be introduced they would most likely be for fighting baddies which would allow for greater diversity in both tactics and health employed by baddies.
Examples of combat improvements outside of pking have been stated in the past including the likes of armour players can hit past but baddies can't. Also if you came up with some sort of creative reason you could even justify a sword upgrade that deals more damage to baddies but not players(a potion or something).
P.S. If you're going to suggest any other ideas, they need to have more thought invested into them such that it's fair for all players regardless of their hours and number of graalats. E.g. cosmetic upgrades based on the number of player-kills a player has would be considered fair and shouldn't cause an imbalance in gameplay.
Now... you might say "but tricxta, such a scheme would promote boosting", to which i'd simply state there will always be noobs who exploit game mechanics, deal with it.
Tldr; in allignment with what I perceive to be one of iClassic's goals: everyone should be on a level playing field regardless of graalats and hours when player killing.