Goodluck with your server but 120gb of ram is a waste it will sit there idol, considering SQL will use maybe 12gb at load and the VMs you run will use say 3-4gb of ram at load also, at 48gb of ram you dont even use 75% of it so it will be intresting to know what youll use th other 80gb for... also as people said sure you got ram but what cpus you got to back you up? would of been better to have 3-4 dedi servers with 24gb or 48gb of ram each. Also upgrade that OS too 2008 and make sure you also have the SQL 2008 editions... its far better than that 2005 stuff...
Goodluck