How to test Service Contracts implemented as OSGi Bundles?

We are in the process of transitioning towards SOA.

Our current goal is to try and ensure that more of the application is developed as "Services" (mainly to improve visibility of capability, re-use and de-risk change). Some of those services will be exposed as web services, but many (and probably the majority) will not, and be used for "internal" use only to help reap some of the benefits of SOA.

For those "internal" services we are currently intending on implementing them as OSGi bundles; however we are struggling to understand how best to test them. Our goal is to enable the current System Test team to test all types of services and we have been investigating tools like SoapUI and SOA Test; however it's becoming clearer that we may face some challenges in testing our services implemented as OSGi bundles using tools like these; and indeed asking the test team to do so.

So we're looking for some advice on how best to test aspects of our capability designed to act as a "service", but implemented as an OSGi bundle instead of a web service.

What tools would people recommend, and is this a type of testing that's traditionally done by a developer during unit test, or can it be done by a less technical tester, undertaking the same basic principles of testing interfaces (i.e. inputs, processing, outputs)?