Beside every item you can see little arrow, if you click on that icon you will see "Find an upgrade on wowhead". That will open a list of every possible item that is better than your current one (with a places where they drop). Unfortunately you can not find gear score table for items ,since final score depends of the gems you choose and enchant for requested item. Just keep in mind that wow-heroes is PvE raiding guide, and PvP items have usually lower use and tho lower score then PvE ones.
