It seems the 3.0.3 version has been removed or EOL by VMware.
The cold clone is a boot-able iso(burn to a cd) for the 2000 box that will allow you to convert it to a workstation vm to a network share that can then be converted to ESXi with the newer converter. I've had to do this on multiple older boxes especially much older DB servers(2000, NT, etc..). If the link to the coldclone.iso is invalid I have a copy and can share it with you if needed.