I have a duplex rental under contract. I plan to close in two weeks. I am set to purchase the duplex outright with my SDIRA. My current custodian is prepared to wire the funds. 

If time allows, I'd like to create a Checkbook Control IRA LLC (let's call it CHECKBOOK LLC for short) for all the reasons cited on various posts on BP concerning the Checkbook Control IRA LLC structure. I am in touch with a couple of companies that provide this service, including a sister company of my current custodian, to see how quickly they can pull this together.

In the meantime, I have been debating whether I want to purchase this duplex outright or not. Since the purchase price, closing costs, and working capital will require most of my custodial account funds (or CHECKBOOK LLC funds). I'm not sure I really want to do that, which leads me to the following...

Since I'm not sure I want to tap out my whole IRA with the purchase of a single rental property, I asked a partner of mine and he said he'd be open to going in 50%/50% on the purchase of the duplex by purchasing it in yet another LLC (an MMLLC that we should call RETIREMENT PARTNERS LLC). He'd bring his 50% in non-qualified cash or via his 401K and I'd bring my 50% via my CHECKBOOK IRA LLC. In this case, my understanding is that CHECKBOOK LLC would be a 50% owner of the RETIREMENT PARTNERS MMLLC (unless there is a reason not to do that). We'd split everything down the middle. My understanding is that my (or, more properly, CHECKBOOK IRA's) half of the rental profit would go back into CHECKBOOK LLC tax-free, irrespective of whether my partner's position is a non-qualified personal position or via his 401K.

Beyond the tax implications, where I am fuzzy is this. And this is my PRIMARY question, given the abovementioned context.. if we later decide we want to keep the rental but want to get the principal out of RETIREMENT PARTNERS LLC to use on other investment, could we sell the property from the RETIREMENT PARTNERS LLC (which has my IRA as 50% owner) to yet another MMLLC called FINAL DESTINATION, LLC where he and I (and maybe others) would be personal owners (i.e. no IRAs involved)? Would the fact that I am personally an owner in FINAL DESTINATION (either majority or minority) owner prevent this sale as a prohibited transaction? I've heard an "expert" say if FINAL DESTINATION is newly created for this purpose, then it's OK. But the language I've read seems to suggest, at best, that I'd have to be a minority owner in FINAL DESTINATION in order for such a transaction to be qualified per IRS guidelines. Thank you.