just in case you arent clear on it, which I think you might not be
if you install esxi, you will need another pc to access virutal machines on esxi.
the only thing you can do on the esxi console is management and host setup.
you cannot get on the console of the virtual machines.
so you would haveto ahve 2 pcs.
1st esxi running vista and ubuntu
2nd pc to connect to the vista and ubuntu machines over the network.