A good mortgage broker will be able to get you something in the 5's on a 30 year fixed if your credit and the property will support it. 

However, given that we haven’t even gotten our company bank account set up yet (I know) we felt it best to bow out.

For smaller loans like that, regional banks and credit unions are often the best fit.

Hello David:Years ago, I had a CPA who done my books and taxes for a few years, decided to quit accounting and go into politics.

What resources do you use to do background checks and credit checks on individuals and what are the costs associated with these checks?

As usual talk with your accountant to get a proper answer :P 

Problem is of course I'm not a US resident for immigration purposes, no SSN, and have no credit history in the USA...although I have a US bank account and debit card and I pay utility bills, etc. so maybe I do have some credit history?  

Setting up a separate bank account is also easy and free in many situations, this will allow you to keep things clean especially at tax time.

You did not account for property taxes. 2.

Worth $500,000. 730 credit score.