You seem to be talking apples and oranges. In the question you ask for feed to post, or rss2html, and in the details you talk about full text. There are many services offering “Full Text RSS”, just google it. I believe this involves parsing the feed, or parsing the links in the feed, to retrieve the full text. If you were using such a “full text RSS” service, WordPress plugins would probably accomplish what you want to do; otherwise, just google “rss2html” or “rss to html” for scripts, which will still require using a full text feed.
See also my quick and dirty webpages: