If you're looking for theories of money management that could work that require more attention and judgment, that might work if you do something, my bet is that your interest only plan will fail in reality,.

Bet if you goggle "notes for sale" you'll find them

While you might find a regional bank or credit union willing to sell you notes, I think your better bet is to work with someone who has a Dealflow of notes and can educate you on the ins and outs of the business.

If you're looking for an agency (Fannie/Freddie) type loan (whether owner-occupied or investment), they won't allow your friend to cosign with you since it has to be a close relative for the sameIf you're looking to cross-collateralize your other assets, a local bank/credit union is your best bet since they can be flexible when it comes to specialized financing situations like this Since your friend is willing to cosign, I'd say form an LLC with both of you as members.

Now once you have a few under your bet and the contractors know you are serious, they will be more likely to get with you for your estimates.As has already been mentioned, BP has some great guides that can get you moving in the right direction. 

It sounds cheap, but I bet it comes with a lot of headaches.

I figure your best bet is to find several people, so if one is busy or can’t do it or bails, you have other options

@Anthony Wick I'm willing to bet that every single one of us have had an unexpected expense in our lives.

I'm thinking vinyl, single hung, double pane will be my best bet. 

Without knowing where the property is, I bet that the units rent for 600+ each in GR.