I need to compile my code for Itanium, but it seems that all of the compilers (ecc, gcc, orc) require an Itanium machine to do so. Any suggestions?
You need to set gcc up as a cross compiler. This involves building binutils and gcc yourself.
The IA64wiki at https://web.archive.org/web/20170428020847/http://www.gelato.unsw.edu.au/IA64wiki/CrossCompilation has a tutorial on how to set this up.