Hi, I am going to invest as a minority (15%) owner in a real estate LLC that was recently set up to buy an office for $700K (my investment would be $100K). The real estate LLC has four partners, two of whom are the owners of a business that is going to be the tenant for the office. I trust the three other partners in the real estate LLC and am satisfied with the legal framework of the LLC and the lease and the property. The lease is for 10 years, after which we'll either sell the office or renew the lease to the business. I don't expect to need the $100K in the next 10 years, and through rent I will have earned back the initial investment in 10 years (approx. 10% return). I am in the 33% tax bracket. I have the $100K in cash or I could use part of my Roth IRA (currently $160K total) via a self-directed Roth IRA. The advantage of the self-directed IRA is that I'd like to put an asset that is earning ordinary income into a Roth rather than my taxable account. The disadvantage is the added complexity to the transaction and the cost ($300/year for a self-directed Roth IRA with the Entrust Group as custodian).

In this situation, which is the better way to invest: cash vs. self-directed Roth IRA?

If self-directed Roth IRA, any recommendations for a custodian (the Entrust Group seems like a good option)?