Migrating multiple content types into WordPress?

I am migrating five Web sites that were built with a proprietary CMS to MU. The sites, together, have something on the order of 100,000 postings.

Data on the site is organized into articles (multi-page, long postings), news items (1-2 paragraphs), and categories (multiple levels, with items listed in multiple categories).

I'm first looking at the question of moving the two content types over: articles and news. WordPress doesn't seem to distinguish between these two types of data, but I need to in order to keep legacy URLs working once I migrate. Here are examples:

For articles:
http://www.mysite.com/issues/issue200910/00002441001.html

For news:
http://www.mysite.com/newsitems/00046719.html

One way of making this work is by putting all the news items into WordPress posts and then using something like Pods to manage a new data type for articles.

But I'm wondering if there's another way. Is there a good way to migrate two different types of content data into WordPress?

Thanks,
David