If you have an IRA, though, you can transfer it to a self-employed solo 401k and then borrow 50% of the balance not to exceed $50K and then use those borrowed funds to buy the property.

If their LTV is 90% of purchase + repairs not to exceed 70% of ARV...then that's the metric you need.  

Brad, my way isn't very creative but we typically lend from a regional bank that has the following terms: 10% of acquisition cost from borrower, 90% loan not to exceed 80% of the “as renovated†appraised value.

In the past, I've gone so far as to actually state the exact amount of property taxes that will be paid by the buyer, "Buyer will pay outstanding property taxes, not to exceed $____."

As a lender, even individuals, the rate asked or demanded will be based on their opportunity costs, thats an economic principal that says he will take the opportunity at that time that exceeds an alternative investment with very similar risk and duration.

Are there any safe, short term places to park a nice sum of money in todays market that can come close to or exceed providing 4.9% return?

However these are very expensive repairs (30k+ in total) and will definitely exceed the rental income for one year.

I was correct on all 4 items and pulled out all of my initial costs and some of the rehab cost via BRRRR and it has positive cash flow today that exceeds the numbers you indicated as your goal. 

Here in CT the sale price of a property often exceeds the rebuilding value of the building due to the value of the land. 

1k + is pretty easy for most spots... even apartments exceed that.