If you have the down payment and just need someone's credit let me know.   

Check the local banks and credit unions. 25 year amortization is more typical for a loan that size so I would make sure 30 yr am is accurate.

My experience with commercial loans in NJ, has been no personal guarantee, because the lender looks mostly at the income potential of the property vs. the business (LLC) or even the owners personal credit/assets...

Let's say that I want to get a mortgage credit certificate (MCC) on a home that I am going to live in. 

Shop around to local/regional banks and credit unions.

I like the idea of lease option for the sake of the Tennant as well as they are more likely to stick around and not cause damages, but I am not willing to tie it up for nothing down without some benefit for me.

I had a similar situation; after calling most major banks/lenders, and getting "no actuary will every approve that," I was able to work it out with a local Credit Union. 

We thought about using credit cards to fund the renovations but don’t want to risk damaging our credit score to do so.

Your Contractor should carry both General Liability Insurance to protect your property against damages, and Worker's Compensation insurance to protect you in the event that a worker is badly injured on your jobsite.Before you start construction ask your Contractor to provide a valid, up-to-date Certificate of Insurance that indicates the coverage that they are carrying for their business.

You do the least expensive and the easiest to repair when the tenants or others do damage.