Why not just go with a cloud server? You can scale your resources up and down at any time:
http://www.webair.com/webhosting-cloud-servers.html
Unlike a traditional VPS (virtual private server), the WEBAIR DEDICATED CLOUD SERVER SOLUTIONS offer truly dedicated and protected resources while eliminating all single points of failure. Additionally, you have the ability for your CPU allocation to burst when there are free CPU cycles on the host machine. So often you end up with far more CPU allocation than what you are paying for!
In a nutshell, pay only for what you use at any given time, & get more redundancy and speed than you would on a traditional dedicated server.
If you are stuck on dedicated :
http://www.webair.com/webhosting-dedicated.html
Contact me, as wel have a couple of specials going on for quad core atm.