Greek collation for UTF8

Hello,
I have a Database in UTF8. There is no utf8_greek_ci collation in my SQL
installation.
None of the existing collations seem to provide an acceptable collation
for greek unicode.

I was wondering if there is a collation for Greek or if not how I might
write one ?

BTW there are two sort orders in common use for Greek. Some locales put
A-Z then Alpha - Omega
Others interleave the two alphabets. So there should probably be two
colations

TIA
Stuart Gall