The wsus reports are ok but simple and don't give anything like an overview for multiple domains. Are you aware of the wsus rollup reporting tool?
http://technet.microsoft.com/en-us/wsus/bb466192
If you can pull everything into a single server then using reporting services or even excel would allow you to put together your own reports as you wanted.
Patchaholic has some good info on doing this yourself: http://msmvps.com/blogs/athif/archive/category/2169.aspx
Other than that you are looking at an MSP type management solution like kaseya or labtech, to name just two. There are a lot of them out there but you're talking quite a bit of cash annually as they independently scan each node and not the wsus server.
Ian