Create a webservice that sets text file charset

We need a webservice that will receive a file and charset and will return the file with the wanted charset. The service needs to require the following: ISO-8859-9 DOS-862 Windows-1255 Payment will be done in the following manner: 20% after the webservice works (we will connect to your server using WSDL). 60% after the solution is working on our AWS instance (this part may require support from your side) 20$ for releasing the source code of the solution.