No one offers both. A criteria of wholesale purchase is that you pay by western union. Therefore the 20% discount includes the 10% WU discount.
As for which dealer offer 10% WU discount I would say nearly every dealer apart from intime and ken.
Puretime and TSwatch are two to name a few.
i can't believe how long time members do not know this and still question my facts . I only joined a few months ago.
I can understand why Ken doesn't give 10% discount by WU. His prices are already much lower than others'. So it doesn't make sense to offer low price + 10% WU discount.