If you are just leveling a second WD and willing to spend gems of ease, removing the level requirements from a couple of set pieces would give you the two set bonus. HT two piece + WoD bracer in the cube is one option. Jade 2 with belt that give you and extra haunt + RoE in the cube would also be powerful.
I'd probably pick chest and leg pieces so you can put gems in the sockets.
EDIT: Leoric crown and ring is the better solution (faster leveling, works with more classes).
You can also put a gem of ease into a weapon for your follower. Also give him a hellfire ammy and ring. These will boost the follower's stats (since he won't have an immunity amulet to start). Equip pet to pick up gold (no need for avarice band).
I use the biggest ancient 2 hand weapon with INT, VIT, and socket (i.e., a stat stick), cube wormwood, bracer that gives EXP when picking up gold, and garg ring. Wear hellfire amulet (sycophant) and hellfire ring. For gems, I use ease in the weapon, hoarder, trapped gem. The WD build is haunt, locust, spirit walk, grasp/piranado, dogs and garg. And do a vault run at T6.
This should put you in the mid 50s. Craft a yellow ring with a socket (powerful gem) and a helmet with a socket (EXP gem). Do another vault. Or switch to cow level or fields of misery to rack up kill streak EXP bonus. If not doing vaults, cube helm that doubles helm socket for more EXP bonus.
Considering crafting a level 70 weapon and rolling reduced level requirement to replace gem of ease with crit gem. I kept the weapon I used at the start of the season.
If you plan on solo p-leveling multiple characters, look for the exp ring and helm that doubles gem power that has a natural main stat, VIT, and socket. Use a gem of ease to remove the level. You want natural main stat, VIT and socket so you can reroll the main stat so it can be used by any class. You want VIT because when leveling crit change/damage won't be worth it.
This is what I did last season and I could solo power level a WD in about 35 minutes. This season, I'd probably use RoE instead of garg ring.