Min specs to install freepbx distro?

Hi everyone,

I am looking for a server to install freepbx distro.

My team is 5 people and max will be 15 people.

I will apply for ISDN PRI line soon which will cater for 30 concurrent calls and 200 numbers.

Note: I may allocate 1 number with 15 extensions or 15 unique numbers from the 200 pools. The rest will be used for fax server (hylafax in this case - but fax server is a different machine).

Any recommended specs for my usage? hopefully not too expensive? do i need to get a virtualised server (1 server that can cater more than 1 virtual machine?) or can I get a normal server will do? means 1 OS in 1 server.

Any help? Thanks.