Hardware requirements for 3 Databases, 50-60 User

Hi Experts,

we are checking the possiblity to put 3 Databases on one Hardware-Server.

Now we have this Hardware:

2 x INTEL 2,4 GHz (Six-Core)

2 x 146 SAS Double Data (RAID 1 for OS)

4 x 146 SAS Double Data (RAID 5 for DB)

24 GB RAM

WIN Server 2008R2 64bit

SQL 2008R2

Is this Hardware (September 2011) suitable for 50-60 current User, working with B1i, Coresuite, Production-Addon (20 user) ?

Please tell your experiences.

Thx

Markus