According to what I have read elsewhere, at a couple properties...that is also about the place that conventional lending starts to become more challenging and portfolio lending and private financing options start to be a better fit.

Pay your private lender back a pre-negotiated fee for the use of their money.

The second option would be to line up a private lender and make a cash offer, on a short sale. 

I have been and am looking for private money partners and I know they exist and I know people doing that very successfully in this area.

Please feel free to comment or message me privately.

if my end buyer uses funds from a private or hard money lender will that interfere with me flipping the contract in anyway or potentially cause any problems?

Is there a way to ensure he does not have them financed to someone else, and also to ensure he actually isn't still paying on them to a private lender?  

It will be difficult to find private money based on your income so your best bet might be to take on a partner in order to do this deal.  

It has a common entrance with four one room with private bath on main floor and four one room with private bath upstairs.

Depending on the opportunities, we'll probably start with flipping and do buy-and-hold at a later stage, both in the Netherlands.In my private time I enjoy playing field hockey, sailing/boating and doing all kinds of technology projects (Arduino, electronics, etc) I love technology, how it makes our lives easier and I love to combine this love with real estate.