Hey Jeff without knowing any details everything is what you are able negotiate. but you have to take in account the years interest rate and purchase price and what kind of cash flow.I will say get a mentor if you’re inexperienced these kind of deals can go left if you really have little knowledge when it comes to structure .

A brand new business getting a loan to purchase a property will almost definitely be at higher rates than what you have now. - When we've review these options with clients the ending outcome is typically that it's easier to forgo the 121 exclusion if you want to keep this property; and do a cash-out refinance (taking on more debt isn't taxable) instead. 

Also, as I build up my credibility as a builder, what is the best financing structure I should be asking for from a bank?

Most SF places needed work, and getting the purchase + rehab loan with a bank was much easier (check with local banks or credit unions, ask for the business or commercial loan department).- Typical lending was 75% of ARV and the loan converted into a normal mortgage after the rehab work was complete. 

I have REPS by actively and materially participating in my rental property portfolio, and also work as a real estate broker full time (1099 collecting commissions through a single member/purpose LLC) from buildings I sell.My losses from my rental properties (LLC #A) largely offset any federal and state taxes from my brokerage business (LLC #B).

But going into business with family can be tricky.

If you have a trusted handy person, you can ask them to walk the property upon guest check out to look for things like leaks, cracks, structural damages, heavy wear and tear on appliances, etc.

TurboTax has rental property features, and the IRS has a great guide on rental income, deductions, and recordkeeping - IRS Rental Property Tax Guide.https://www.irs.gov/businesses/small-businesses-self-employed/tips-on-rental-real-estate-income-deductions-and-recordkeeping2.

Also, I'm not sure why they approved my plans and asking for a zoning permit now :(  They are asking for architectural plan of the old structure - I'm not sure if my architect has it. 

I am meeting with an attorney in the next few days to discuss business structure, and other things, and after that my goal for March is to have a meeting (along with my business partner) with an awesome MLO that was recommended by the great @Jonathan Klemm .Important thing I wanted to plug here is a free mastermind meetup I am planning for March around Naperville.