Great stuff! A while ago, I posted an
Amon Hen scenario on the Song of Blades Yahoo Group. It might be of some use - the idea was to have a heavily asymmetrical battle that could conceivably result in Boromir's death, along with the deaths of four Isengarders and sixteen other orcs ...
(I'm not sure if the Mordor orcs should actually be present at Amon Hen - running it with just Northerners and Isengarders would be simpler).