This is an area where I have some experience, which I am glad to share here without the corresponding fees
I know there are others in the field who are on the board.
I work mainly with foreign investors in fixed income, so our focus is on bonds, since dividends do not have the tax advantages over interest income that they do for most US investors (the opposite is mostly true).
However, if we are talking about IRAs, where whatever happens within the account is irrelevant for tax purposes, income from bonds and particularly high-yield bonds can be more advantageous than seeking income via dividends for a US person.
There's a little more complexity in trading bonds than stocks, particularly online, but it could fit well into a fixed-income strategy for a self-directed IRA.