All the buy-write funds characterize part of the distribution as ROC, which is, I believe, the major part of the tax management strategy. Some dividends are also characterized as "qualified," but this tax break may be going away. But it does not cost anything, so I hold these in both a Roth account and a regular account. You can buy and sell these in an IRA without the tax consequences, i.e., the work of tracking your capital gains and losses, that you would need to do in a taxable account.
Here is a good screener to get you started on your research: http://www.cefconnect.com/Default.aspx Some really wild price swings amplified by discounts/premiums these days. I like to trade these in my Roth accounts---hard to buy and hold with these swings.