I got the sitemap running as you described (followed the K8 docs) and that certainly gives me a much cleaner sitemap.
There is another related issue though. We are using jQuery tabs on several pages, and want to treat some of those tabs as their own page. We have some custom code that lets us navigate to a specific tab via URL. For example I have example.com/sales. There are 3 tabs there, and I can navigate to them by using something like: example.com/sales (goes to tab1), example.com/sales/cars (goes to tab2), example.com/sales/trucks (tab 3), which will spit you out on the right tab. This is working great.
Now I need my sitemap to reflect the fact that my page "sales" is actually 3 pages. In other words I need my site map to reflect:
example.com/sales
example.com/sales/cars
example.com/sales/trucks
and this is why I was attempting to work my own sitemap. Any ideas on how to do this with the set up you describe? If I could edit the resulting xml file and add my aliases then I should be in the ball park. Since the webpart sitemap is dynamic, and created on the fly, I don't know how to edit it.
Another thought is I could save the dynamic googlesitemap.xml, then edit, then just drop it in the root, in the "traditional" manner.