I don't know too much about Portal Server, in fact, I am deciding on one for my projects. But I must say the portal to choose must provide you with a proper separation betwen End User Interface and Business Rules, to let designer to work without to much problems. With this aproach you may consider Portal Servers designed with Struts or JSF (Java Faces) technologies (or equivalent). I know other technologies like Zope/Plone written in Python , that works fine separating this matters (www.plone.org), but there is no enough documentation for newbies compared to Java. (This site seams to be developed in Plone!)
I don't know too much about Portal Server, in fact, I am deciding on one for my projects. But I must say the portal to choose must provide you with a proper separation betwen End User Interface and Business Rules, to let designer to work without to much problems. With this aproach you may consider Portal Servers designed with Struts or JSF (Java Faces) technologies (or equivalent). I know other technologies like Zope/Plone written in Python , that works fine separating this matters (www.plone.org), but there is no enough documentation for newbies compared to Java. (This site seams to be developed in Plone!)
Good luck,
Edu