1) the "disk" configuration you gave us is almost useless from an "is it configured well" perspective because you gave us no idea about the underlying IO subsystem configuration other than RAID type. A 1000MB "disk" could be a single 7200RPM SATA drive shared by lots of other stuff or it could be a slice of a 3-PAR 1000-spindle SAN that can support 300K IOPS. You, as the SQL Server DBA, simply MUST know EXACTLY what underlies each of your "disks" and also know anything else that might share the same IO pieces-parts.

2) VMWare can support MASSIVE amounts of RAM, CPU and IO now. IIRC 2TB RAM, 32vCPUs and a system was benchmarked at 1MILLION IOPS on the IO side. I assure you that a properly configured VMWare system can support your 300GB database with a few hundreds or a few thousands of concurrent users. I note that that doesn't actually mean your database and applications can support that! :hehe: