A program called Comic Book Creator is more in line with what you're looking for, I think. It allows you to create comics with word balloons, an array of different panels and can export either as pdf, jpeg or other formats. Unfortunately, as I look at their site - planetwidegames.com - I'm not sure it's still available in this format. Looks like it's more designed now to create content for placing on the web.

There still might be a source for the original program. Cheap at around $30.