Quote from @Rick Im: Does anyone know of a lender that offers second mortgages on rental properties?

Their pro formas felt optimistic with providing 6% annual appreciation and property management that is only about 6% of rent so I take it with a grain of salt (they offer their own property management services but it has terrible reviews on Yelp so I would probably go with someone else). 

What are the pros and cons of each, and which offers the least restrictions, flexibility and cost savings for my intended purposes?

Now, moving forward he offered for us to take it over completely.

The offering would be at 490 units at $1000 unit

I've worn three hats in the seller financing world (as a property buyer, as a property seller offering terms, and as an investor that buys seller financed note). 

For future readers, many banks will offer an unsecured line of credit up to $25k.

Both Conventional loans and DSCR loans can offer this flexibility, depending on the specific scenario and borrower qualifications.

This property offers spacious townhouse like setting floor plans offering one, two and three-bedrooms.

@Christopher Smith there are many...but in my opinion really only three companies out there that offer the ability to 721 into a large and diversified REIT that i'd feel comfortable with.