web page with data from two sources

We do all of our static web pages for our public site on IIS and use Dreamweaver to create them. We do all of our dynamic web sites from the iSeries. Our public site group would now like us to generate simple single pages (a list of employees for a department) and also multi-page apps (like a shopping cart app with multiple steps) imbedded inside their pages. So they control the header/footer and left navigation using Dreamweaver running on IIS and we produce the code for the content part of the page. We want to stay with writing java apps that run under Websphere on the iSeries and not need to also start developing asp code for IIS. I have never used them but I think iFrames would do what we want but no one wants to even talk about using iFrames at this point. We almost are wanting to build something that acts like a portal and the iSeries apps would just be portlets/webparts. Has anyone done anything like this?