I am wondring what the differences are between the above?
Not a great deal. The bottom two are more frequently referred to as Representational State Transfer (REST). Google for [REST vs SOAP] if you want to read up on it.
Unless you have a reason for using SOAP, I'd use REST. It's easier and more efficent.
If you just want to output it in a readable format on the web, grab the XML document using your programming platform of choice, convert it to HTML or XHTML using an XSL document and an XSL processor and output the resulting HTML/XHTML document to the web browser