You need a solid proven system to find the deals.  

I have the ability to find properties that all in costs including rehab and purchase would only be 70 to 80% or ARV on properties. due to this I have been trying to find lenders that allow for less down and rehab coverage since the properties are so discounted.

The one stop shopping is definitely the appeal, but remains hard to find.  

These days the hardest part for me is finding & keeping qualified contractors for the work that always needs to be done.

Connecting with local GC groups in your area will help you connect with subcontractors, find out tips and tricks of the trade in your local area (since all areas and their real estate differ slightly).Also, have you considered the motivation behind building a brand-new duplex versus finding one on the market?

I think it's just a matter of being a bit creative and finding opportunities to add value to a property.

I find that in every group. 

We were extremely hard pressed to find a painter to do this which is why I said I could do it.

Try to find a property manager that also does sales / brokerage.

How did you find this deal and how did you negotiate it?