How to be an IRA custodian?

Factual Questions
1

I’ve been searching the web (and especially the IRS site) but I cannot find anything related to the requirements for being an IRA custodian. (Note for non-USA Dopers: “IRA” is an Individual Retirement Arrangement – a way for US folk to plan for retirement.)

I am not sure if this is limited to banks, or if a non-bank “financial services” company could fill the role.

Why I am looking: I have found that very few IRA custodial firms will handle an IRA that has invested in ownership of real estate. It is apparently a very complicated, paperwork-intensive project, and I am willing to bet that the firm that is willing to take on this task would have more than a few clients. Seeing as how I’m a dork in that I love paperwork and complicated, gargantuan tasks, this seems ideal for me. So… how do I proceed?

2

I will leave running the numbers to you and your investment advisers, accountants and attorneys, but I’d hazard a guess that the reason most people don’t want to have real estate in their IRAs isn’t the paperwork burden that stops them from putting rental properties in IRAs, rather, it is that rental properties are such a good tax investment due to depreciation rules that allow one to have positive cash flow and still report a taxable loss, that most people would rather not have real estate in an IRA account.