You might could sell the land off for commercial development and let them tear it down. 

From there, you should be able to develop a list of contractors who can help.

It is very difficult to structure a PE deal when the other partner(s) is not also bringing cash in or is in some way developing/renovating the property.

In any profession there are the talented and trustworthy and wholesalers like yourself are the exception but as you can imagine all the newcomers with little experience,who just took some webinars,have little cash or credit and have not developed their end buyers is the vast majority. 

New subdivision being developed or out-lots in an existing community?  

I develop and broker towers for all of the carriers and it is a very niche form of real estate that I really enjoy.  

However it is a planned unit development (PUD) so the owners pay monthly dues to an association, sort of like with a condo.

Develop and document the system, train someone who is not a seasoned technician, and follow up to make sure he/she stays on track.  

Find parks in your area, forget those parks, they are 98% over priced, contact those brokers and develop a relationship.You will need a credible team, proof of funds for the down, or a cash partner who has the down funds.We did the above for 1.5 yrs post Frank and Dave's boot camp.  

I agree 70% rule is kind of simplification, but finally i see the main difference between flipping and building is that while flipping goes you earn money on buying with cheapest repairing, but while new development/deep rehab goes you earn money getting adding value for highest market price comparing of rounded properties in this location.