Old setbonuses have been removed from the game (not just in pvp). There's a few oversights but they are irrelevant at level 70.
The question about ilvl depends on your level. If you are twinking at 79 (don't) you should go for the highest possible ilvl. But if you are twinking at level 70 there's no point since a level 70 character has no way to reach the required ilvl threshold to start increasing their stats in instanced pvp. Just make sure you are wearing the correct armor type for your class in every slot and that your average ilvl doesn't go below 115.