Recently, I made
an RSS reader called Feedani.
It can get feeds from sites that support RSS and also from many that do not.
Just copy/paste the page's link to the "Add" dialog.
You can save any article by right clicking and selecting "Save page as epub".
It saves only the article part of the page.
Finally, there is a hidden option to save any page to epub (not only the feed's articles), by pasting its link to the dialog you get if you press alt+X.
Try it, and tell me what you think...