Charset Conversion Experts

Hi, We have an PHP application which grabs data from various websites through RSS Feeds, Web Pages etc. Our internal system is UTF-8 while the websites have different encoding being used, some of them have Windows-1252, ISO-8859 among others. The web pages are coming in from all countries and in different languages. Your job here is to create a PHP based encoding solution (a class / a function) which will correctly encode the incoming data into UTF-8. We can pass as a parameter the source encoding. The test of this solution will be that the text displays correctly in our MSSQL database and PHP web page which is UTF-8. Please do not think in terms of simplistic solutions like mb_convert, iconv since all of them seem to be having issues. We are looking for deep demonstrable experience with the issue. If you have a solution for a specific source encoding, you are welcome to post a bid as well.