If you are using the code I linked to, I'm sure you can add the image into the $rss_output variable.
HTML Code:
$rss_output .= "<dt><strong><a href='" . trim($link) . "'>" . htmlspecialchars(trim($title)) . "</a></strong> <img src='path/to/image.jpg'></dt><dd>" . htmlspecialchars(trim($description)) . "</dd>";
I don't know how to modify that to put two threads in a row. I suppose you can introduce a counting variable and when odd, you do one thing, when even you do another, and you can play around with it that way.