Silk,
Although I don't think that the I shares S&P Index has options, many of the products do. They have just about every index under the sun, so it would be worth a look. OEF is the S&P 100 product, and the last time I looked there were options available for it.
Now, for my question, have you ever considered the merits of selling puts instead of writing calls? The risk is similar, and there is a little more flexibility. I used to sell a lot more covered calls than I do now. The biggest downside that I see is that when you get a snap back rally you are holding positions that can cost you more to get out of than you stand to make.
Also, if the put goes against you, you can short the underlying to mitigate your risk.
Regards,