Maybe talk with a local bank or credit union and see if they'll be interested in a portfolio deal.  

Qualify the lender to make sure they give you income credit on the home from the rent (usually 75% of gross); your required down will go up 5% on the 5th - 10th mortgage (ie: 20% to 25% on SFR); and you will need to keep extra reserves. 

I've got a 780+ credit score. 

Is there anyone on here that is a credit specialist?? 

It sounds like you’re dealing with a speciality product, but localBanks or credit unions tend to keep their loans on their books and may be willing to get more creative.

And like others mentioned, take the time to get a quote from credit unions.

I already have 4 loans and finances are in pretty good shape with good credit score above 750and am in Atlanta, Georgia.

The smaller banks/credit unions in Fort Worth do not seem to be willing to refinance investment properties - Colonial said that they would, but they want me to have less than 4 investment mortgages and I've got 5... 

The last time I looked at the issue, the 30% federal solar tax credit was only available for personal residences (not investments/rentals).

Are their any special tax credits I should be using or looking into?