I will just comment briefly on your retirement account you mentioned.

If they dont have a product for you ( and it will cost you probably about half of what HML will cost.. then you will have to start looking at HML.other thing is friends and family or borrower from you retirement account.

I would recommend a cost seg study immediately after purchase to take the benefits of bonus as is and then look at doing a cost seg after renovations to take the benefits of bonus on renovations. 

Depreciation helps reduce the taxable rental profit, potentially bringing it to zero or even creating a loss, which can carry forward to offset future rental income or other capital gains.For high wage earners, other tax strategies could include leveraging cost segregation studies to accelerate depreciation on rental properties through bonus depreciation, taking advantage of tax-deferred exchanges (like a 1031 exchange), or maximizing deductions related to property expenses (mortgage interest, property taxes, insurance, repairs, etc.).

Talk with a local realtor and tax accountant.  

While completing a Cost Seg study, they were very resistent to me using 6% and because of time-sensitivity, I decided to default to the "rule of thumb" method that you mentioned and used 80/20. 

I can't talk price, I don';t even know I just signed up, added a VA account, a 2nd zip and am working leads.   

A condo HOA can decide they want to replace all the roofs, but if the bank account is low, hit you with a $5,000 special assessment.

Therefore, you cannot go up to 85%, Account Closed.

According to several studies (Google it!)