Source for Investments (notes, tax liens, private lending, etc.) for SDIRA?

[John P.]

I recently set up a SDIRA with uDirect. I was planning to do a loan to a non-RE business, but am having some second thoughts. As far as RE investments go, can anyone recommend a good source for notes, deeds, tax liens, private lending, etc? By "source," I mean a person or company who specializes in such things--especially one who has worked with qualified plans like IRAs, solo 401ks, etc.

Jeff Brown mentioned that he has a source for notes on his recent podcast (#17), but didn't reveal who it was.

Thanks.