Hi Kevin, I currently recommend [removed at their request] for servers.  Their lowest-end CPU and 1GB ram should be great.  If you don't need to host a lot of domains or email accounts I could configure a bare-bones server with no control panel.  If you would like a control panel I recommend Plesk or cPanel.
I can do a setup of the server and ListMail for $150 and do ongoing management and monitoring for $25/mo.
Regards