Time to prepare a long-term migration?

Hello Admin Wizards,

afaik the "official" support for Tru64 will end within the next years.
So it seems to be about time to think about the long-term-future of our 
server system.

What product would you recommend as a worthy successor for Tru64 in 
respect of stability and reliability for the services:

file sharing (samba services)
Web service (Apache)
Database (PostgreSQL)

and some minor applications based on php and jolty scripts?

Security is also a topic. I had no single successful hack on the Tru64 
boxes in the last decade whilst the linux systems four times suffered 
from serious attacks.

Would be grateful for any advice

CW