What bandwidth are you using? I currently have all my stuff in the process of moving between my old plesk/fedora core 1 vps to shiny new centos 4.3 cpanel/whm one. It has a 1.5mbit duplex connection and unlimited bandwidth. When I changed server size with rackforce the downtime was only a few hours.
The old server is costing about £40 pm for 10gb of disk, backups and firewall. The one is slightly cheaper as the fantastico is $2 a month rather than $10 a month for the plesk application vault. The new one isn't migrating the old stuff too well unfortunately....but if you stick with the same control panel in any migration it is usually seemless.
Yes I know I should be writing this road charging thing....
I still haven't done the job application either