I find Espeon cuter (*waits for all the Gardy club fanatics to pounce*), but Gardy has the better movepool, with access to Bolt, Magical Leaf, and Ice Punch. Use Mullet's set for Gardy (though add ML as a third choice for the Ice P/WoW slot, since it helps with the bog mutant), but for Espeon, I like to capitalize on its high Special Attack with at least two moves:
Espeon@Lum Berry
Modest, 252SpAtk/128HP/128Spd
- Synchronize
Psychic
Bite/HP:Special
Morning Sun
Calm Mind
Wishpassing is fine, but Morning Sun+Wish is pretty much the same as OL. One or the other to free a slot.