I'm a fan of ADUs, and through my research, you may want to try a Modular GC who works with a factory to get you the dwellings you need. 

They are purchased with chattel (personal property) loans.Modular homes are similar to stick-built, but large sections are built in a factory and shipped to the site to be assembled on top of either a slab or standard excavated foundation. 

One factor is, Which is the better deal?

If that's the case you should get additional forced appreciation from bringing better management.I think this deal is solid if the hassle factor is low, the apts are reasonably low maintenance and you are very confident of your pro forma numbers.

The most important factor is finding a good company to partner with in a strong market.

It is a little bland.I like the warehouse or factory.

Depends on if the "Modular Home" is a mobile home are a "stick built in the factory" home.  

As mentioned above, there is no standardized factory line model for the ideal company.  

Other factor is price.

I am not sure the $0.50 maintenance factor is the best to use.