lquigley is correct, trying to implement / use SOAP probably will not work with that platform - unless it gets extended later on down the road. Regarding DataExchange, it is purely SOAP. You can, however, work around the SOA of this SOAP Web Service and construct your own XML as a parameter (“sXML” being the request parameter) and submit the request via POST.
In the long run the RESTful API will definitely be the way to go. Since it is strictly RESTful it assumes HTTP and that is really all it needs. If your code can understand the basics constructs of HTTP actions (GET, POST [Low REST], PUT, DELETE [High REST]) and request / response then you’ll be up in no time.
DataExchange is strictly an XML based RPC so it will be difficult to use in a "web friendly" environment and is more keyed for machine to machine interaction - its primary purpose is to transport large amounts of data in and out of F1. The RESTful API will be just the opposite; a full-fledged web/human friendly API built specifically for uses like those mentioned above.
--Nick