You do not need that. FPC comes with fcl-web and that contains more than enough to write webservices.
I believe mOrMot is also suitable, as is the Brooks framework. The latter two are third-party, but also opensource. WSDL may be an issue, I believe all these do not have a wsdl importer. WST does, but I did not use it for a long time. I used Delphi for that and changed code by hand.