Which version to choose


I need to install a smal VoIP server, 8 phones will be connected to this server. The operations to handle are really simple (mailbox, transfer, …).

The infrastructure will be 100% SIP (no ISDN, no PSTN).

The main focus is the stability of the system.

Which version would you choose between Asterisk 1.4 and Asterisk 1.6.1?

Many thanks in advance for your help!