typically you wouldn't use both SS and Adapter models in 1 project. that's not to say you can't, it just doesn't make sense.
There is a section in the documentation about determining which model best suits your needs. In summary SS is good for simplicity, single database connectivity, and apps where db logic can be a part of the presentation.
The Adapter model is good for mulitple database access within 1 model, webservices, and strict n-tier methodologies.