There is another way that might be easier. Companies like Broad Financial can help you set up an IRA LLC that is wholly owned by your Roth IRA, and which you manage. These are often used to invest in real estate, but you can own bitcoins in them, too.
You don't have to be an accredited investor, and you don't have to let someone else secure your bitcoins. As the manager of the LLC, you're responsible for securing the private keys yourself.
See details at
https://bitcointalk.org/index.php?topic=396783.0.