Hah, nice piece of trivia, I didn't know. How are the item levels down at level 200, because droprates and stuff are based on dungeonlevel right?
It might be easier to find weapons with higher +to_hit and +to_dam values, or armor with higher +ac, but that would be unlikely to matter much, because you'd be using artifacts anyway.
I don't know if rings of speed take dungeon depth into account. Most other types of bonuses in the game are capped. (e.g. a Ring of Constitution +6 is as good as Rings of Constitution get.)