@jeff khel thanks for your input, I ended up retracting the contract as the homeowner had all these additional stipulations indicating she wasnt as motivated as she claimed she was.

The stats are: -5 stories totaling 20,000 square feet above ground, plus a full basement which is partial commercial space and partial tenant storage/utilities-First floor commercial space is around 2300 square feet with an additional 1500 in the basement, 12' ceilings in the first floor-14 residential units above, most have private balconies or decks, elevator, bike storage, mail room.

Will make sure to add it!

In addition to have a loan officer, or broker, you will need to add to your team at a minimum such experts as GC's, insurance brokers, home inspectors, CPA, attorney. 

In addition, if i were to find a bank that offers this package, what kinds of hurdles should i expect to encounter before loan is approved (e.g. appraisal, state/local ordinances, etc)?

With every additional unit, you slightly reduce your tenant risk and find that valuations are better on larger assets.

Our family has been renting a single-family home (see description/additional background below) for the last 2 years and are considering buying the property from the landlord via private sale.

Our goal is to add an additional 25-35 in the next 5 years.

In addition, once you've freed up your equity in your current home and invested it in income-producing real estate assets, consider applying for a couple of FHA multi-family property loans (4 units or lease) which have competitive rates and low down-payments (3.75% at the time of writing this). 

Speak to your banking representative and they can give you some additional options.