Most lenders are going to be limited to using the lower of appraiser's opinion of market rent or the actual in place lease (or in some cases 110% of market if lease is greater) so it sounds like you just need to roll the dice on a new appraisal but I'd recommend having some rent comps on hand for the appraiser up front just to avoid the same issue.  75% cash out pending positive DSCR is widely available at most DSCR lenders. 

Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

Has anyone worked with these or other coaches they would recommend?  

I wouldn't recommend Philly for a variety of reasons.

We recommend holding off on the invoice until you receive a terms sheet outlining the loan details and a clear breakdown of the appraisal fee.

I recommend putting the final lender tab at the top of the page. 

or any recommendations on which is the best Bank/lender to get one with the best rates? 

Which zip codes do you recommend for investment in Detroi?

How do you recommend we go about getting this goal of the ground ?

I found that most of recommendations to buy a duplex emphasis on positive cashflow or match with simple 1% rule to start with.