Be a bit mad to have duplicate content, messy and the trying to keep both in sync would be a nightmare. You also want to consider duplicate content in the eyes of Google.
Your best bet would be to leave the content as is (only one copy), but have duplicate navigation. There are many ways to do this, one would be to have categories Section 1 and Section 2 in say a navigation category group. Then you can render out all the entries associated with each category to build the relevant navigation (and entries can reside in both navigations). The ordering can then be set to either alphabetically by title, or random.
Also with categories, if the client really, really, really wants to have two separate URLs to the same content (based on service route) and you can't convince them otherwise, you can use categories in the URL and then pull the url_title from the last segment then use as channel:entries parameter and not use structure page_uri or er, page 'structure'. So the same entry will be used for both URLs. This doesn't mean you don't use the Structure module, you're just not using the URLs that it's producing (or you only use their URLs for one of the sections and a category based URL for the other).
You don't need a category identifier in the URL either, just use segment_1 that matches the template group. For example, in Structure have a parent that is "Services" which then has child entries for the 50 services. Then have either 2 template groups "section-one" and "section-two" which list out the relevant services (segment_1 equals the template group), and then segment_2 is used to pull the url_title into the channel_entries showing the details for the relevant service. Alternatively for more flexibility have 1 template group called "services" (segment_1) and then use the category url for segment_2, then segment_3 would be your url_title.
Remember to use dynamic="no" and url_title="{segment_3}" for the channel:entries parameters.
Alternatively look at Navee to generate the navigation.
If you really want to pursue duplicate content, the only plugin I'm aware of is Cloner, but that's just for copying it, and not sure how it will behave with Structure.