Hi, started with .asmx services, then I used WCF .svc, since a couple of years I'm using REST API, but as you can see in my feedback I've solved .svc issue to freelancer customers.
I love this kind of challenges, I'm willing to do a proof of concept without been even awarded, I'll asume the risk, do you have specifics URLS both for downloading and uploading the SOAP XMLs
Thanks,
Felice