Maybe look at get inna's set or nat 2-3 set?
Also, I don't know if a ruby is worth getting on a manti with 34%+ wep damage. I think maybe double emerald will give you more dps. But you should test it.
Looking at your skill build. How are you going to regen disc with out a nat legacy or Night stalker??? As a DH you need disc to stay alive.
Decent build overall, 7/10.