If you are upgrading from an MCS based version (pre 9.1) to a Portal based version (9.1+) and are using DDA's in your current system, the expectation is that you use Page Builder. The only exception to this would be if the needed functionality from DDA’s is not available in Page Builder.
Page Builder documentation is in the Administration > Extensions section of the OnLine Expert (the online help in the Portal). There is also web services documentation (web services are often used within page builder) in the MOCA Developer Guide.
