In such a case I would go to UTF-8 (Unicode). A few days ago I posted what we have done to "unicodize" moodle. If you search for "Unicode" you should find my postings. We test on Solaris / Postgres. If you need a test account or want to create the new language pack for UTF-8 on our test server let me know, I've already done English, French and other languages (email me apart of the forum). Once it is working, you can give the lang pack to your technicians (and share it with the moodle community). Please be aware that it is really not a good idea to mix various encodings in a db (eg. ISO Latin 1 and UTF-8).
Setting up Moodle with Postgres is not a big thing, esp. under Linux you should have all the precompiled binaries available.