Linux Application Server

Looking to falsehood a scheme server. I hit windows 2003 server, still I would same to ingest a linux / unix server. What is the prizewinning opensource computer for me to ingest and WHY?
I meant an operative grouping to separate my scheme computer on. A linux / unix operative system

I hit 1 mercantilism server,1 Domain controller,1Backup Domain Controller ,1 UNIX scheme server,1 covering server,1 enter server+print server.all of these do 400GB in data. And I poverty to Backup every these, I hit bought 2x WD My concern 1TB Hard disks with 1 Gigabit Ethernet and I requirement a patronage plan.Anyone that could help?Should I sunchronise with synchbak ? Will it do my work?
George From Ellas ….help WILL BE appreciated…