We worked with engineers and architects to complete the design phase alone and combination of a General Contractor who pulled the permit for us, our subcontractors, and our in house renovation and maintenance team to complete the work.

From there I can obviously back out equity and financing fees and figure out what I can pay for the land... that's my goal at the moment.Looking for some insight on how to better estimate construction costs as well as an architect that would fit this project size and maybe any suggested financing structure aside from bank construction loans, which are extremely hard to come by these days. 

Best to find a local Architect. 

There are multiple books on amazon about estimating rehabs - but from your questions, it's probably best to start talking to an architect about what is even possible.

By the way I was a SW engineer in San Diego (a JSF architect), that house hacked my first house (but it was a SFH, not 2 units).  

you dont need an architect $$$$$$$$.

If so look for some reputed names or contact a local architect to get some referrals.

A good team: Rental Manager, Attorney, bookkeeper, architect+contractor (for remodels), and handyman (for repairs).2.

Is the architect providing any other design services (finishes, layouts, booth design, cabinets, partitions)?

My wife's an architect so the goal is to become a design build company.