You might want to check with local credit unions or community banks, as they’re often more flexible with second mortgages. 

Generally, the properties that benefit the most from a cost segregation study are properties that are remodeled, expanded, purchased or constructed after 1987, the year in which the Investment Tax Credit was enacted.

As mentioned seller credits are the best path as title insurance and taxes are pretty much fixed.

Credit card receivables are much more clear cut.

Your best bet for that size will be local banks and credit unions, good luck.

If you develop a great relationship with local credit unions, you'll be surprised by what all they're capable of.   

Perhaps as a syndication or credit fund?  

I have $80k liquid in CDs and savings accounts in the bank and a credit score between 760 - 780.

I went to my local credit union, Wells Fargo, and United Bank and each one turned me down after "checking with legal."  

For the 2nd applicant, her credit score shows 770.