1) Tyrannical Gladiator
It would be nice if we could get back the Tyrannical Gears or Arena Season 13 gears for Xmogs and whatnots. Not many people were able to acquire the gears and i have to say it is truly a pity since back in the early days of Warmane's MOP. The game was filled with bugs and we didn't have much players who would stick with us all through the hardships.
Now with the hard work of Warmane Developers, MOP is better scripted, well-adjusted and we get new players regularly. I would like to propose bringing back this old gears namely Tyrannical Gladiator Gears even just for the sake of Transmogs.
Example for Implementation in-game : The Tyrannical Gears could cost as much as the Grievous Gears right now our could cost a bit less. People will still be willing to buy it even with same prices as Grievous Gears. I'm sure of it.
2) Dreadful Gladiator
Now this is an old Arena Season 13 gears which I didn't see at all even though I started pretty early playing MOP on this server. I only remember getting the free Dreadful Gears for free back in the Moltdown days. This is also a gear which I or We would like to see again.
Example for Implementation in-game : (Same as Tyrannical Gladiator Gears as suggested above)
You could also make these pieces purchasable by gold especially the weapons, In that way you can have a gold sink and enchants wont cost alot. Might also help the gear gap in pvp for new players and gearing alts.