Please guide me on how to do this deal. Thank you in advance.

1. Brother buys an ugly empty fourplex for $150k, then adds another $50k to fix it up.

2. 6 months later, property is now fully leased at $3k in gross monthly rents. Property appraises at $250k, so brother refinances, pulling $200k out of the property, leaving $50k equity.

3. Perhaps another 6 months later, I buy a 50% interest in the *equity* of the property, for $25k, using my self-directed IRA funds. ***Which self-directed custodian would allow this?***

4. Deed is filed with 50/50 ownership, with brother's name and the name of my self-directed IRA both listed. This theoretically triggers a default clause on the loan document, but as the mortgage will stay current, lets assume nothing happens.

5. Property management company is hired to do everything. Because fourplex cash flows are large, all expenses and even larger repairs would be "netted out" or "pre-reserved" so that my IRA does not have to actually get involved in cutting checks.

6. As loan would still in brothers name, he would still get the 1098 showing all mortgage interest was paid by him, and thus that is the amount he would file. 

7. My IRA would be hit with a large UBIT tax of 33% or so, on about 80% of any profits, but the leverage to me is worth it. And since my brother is not a lineal relative, it would not be a prohibited transaction for my IRA.

Where are the landmines?