Yes, I think you should be fine
CRM Requirements (CRM 2011 requirements are on this page and also in the Implementation guide). You meet those
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=0c7dcc45-9d41-4e2e-8126-895517b4274c
SQL Server 2008 R2 Requirements list 1.4 ghz as a minimum, but you have 4 CPU's so you should be fine on the 1.4 GHz minimum issue
I would maybe install trial versions first before you buy and try it if you are still nervous.
Jamie Miley