Have you tried putting your images and text together, as in making a image file, adding some canvas space at the bottom and adding text and saving it? A lot of people seem to do it that way. It doesn't give freedom to the reader in formatting, but it does help in your case.
But yeah, KF8 is probably what you're after, specifically the <figure> and <figcaption> tags. Here is the supported list from Amazon:
http://www.amazon.com/gp/feature.htm...d_i=1000729511