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

Does anyone utilize a line of credit as an emergency fund?

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.

and how well my credit score will be?

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

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.   

Credit scores are made up of many factors, one is the utilization of an account vs its credit limit.

Hi Nate - It'd be worth asking the lender for a detailed breakdown of closing costs for this program, as well as an estimate of the interest rate you'd get with today's rates (they'll probably need to pull your credit to do this).

Perhaps as a syndication or credit fund?