There is no silver bullet when it comes to a testing strategy or tool for SOA based applications. The strategy and tool very much depends on the underlying SOA architectural landscape. The technology stack of 2 SOA implementations can be entirely different. The architectural style can also differ. Individual webservices work together to form business processes. There can be 2 main ways in which the webservices talk to each other. Orchestration and choreography. As the name suggests, in the orchestration style, there will be a router service which will coordinate all the other services internally. Choreography style requires all services to be aware of their individual responsibilities. The testing strategy differs in both these cases.
Similarly, when it comes to tool selection, it depends on the interception points, the tools ability to intercept, publish , subscribe from endpoints etc.
In short, test strategy and tool for SOA testing can be finalized only after a thorough landscape analysis every time.