I require they have at least one times the rent in income vs the three times I require of non-voucher holders.  

I know most of them, happy to recommend.   

You should look at what the other rentals in your area are doing.

Looking to continue to add more to my portfolio as well.

While renovations faced delays, and initial rental demand was slower than anticipated due to construction setbacks at the casino, the property is now performing well as a long-term rental.

Any recommendations or suggestions for ways to negotiate this (and not lose our earnest money)?

If I were you, I would focus on one or the other (sell a greater # of payments through the partial, or hypothecate at a higher LTV.

Looking for some advice on how 1031 will view rehab costs/ ARV on something like this? 

Your daughter can gift you the $31,000 equity by selling the house to you at a below fair market value price.

@Kaleb Ahonen looks like you really want to learn.