We’d prefer to not deed their interests to 2 separate SMLLCs as this creates complexities with having to maintain multiple bank accounts, etc.

Does anyone have any experience with the cost ballpark and requirement to do this with a single residential (not multifamily complex)? 

Hello Bigger Pockets Community,I recently transitioned into specializing in multifamily real estate investments and have been immersed in learning about the complexities and nuances of this space.

These professionals can provide valuable insights and help you navigate the complexities of real estate investing.Research the market: Start by researching different markets across the country to identify areas with strong rental demand, affordable property prices, and potential for appreciation.

Typically, banks, funds, and traders will have an expectation or estimate on key economic data releases, often created through sophisticated, complex financial models.

I also know that my apt complex is in a Turkish Fund for an investor.      

Definitely get the estoppel letters and copies of existing leases.Apartment complexes change hands frequently (if judging by the "under new management" is any indication) and I can assure you they don't kick everyone out and start from scratch.

That would clarify what you are trying to achieve.LLC with a good operating agreement.SyndicationREIT fundEach one has an increasing level of complexity and reporting requirements 

Plus, managing an LLC adds complexity, requiring adherence to state regulations and additional paperwork.

Be careful; the rules for qualifying for a real estate professional are extremely complex - it is an area of the tax code that many practitioners and even judges (tax court cases) have gotten wrong.