If you are going to go the ESXi way you might as well use the vCenter Converter Standalone client. It is free. You can run it from a laptop. It is fairly straight forward. You tell it where the hypervisor server is and you tell it the ip of the physical server you want to migrate and it pretty much does the rest.
But before you can do that you need a properly setup ESXi Hypervisor and from the questions you are asking about ESXi VMWare Workstation I have a feeling you are missing some core parts. Mostly because you don't want VMWare Workstation. You want ESXi on the server and vSphere client on your workstation to manage it.
I'm all for trying things on your own, but if this is for a production server I'd suggest hiring someone. Migrations are filled with little gotcha's and the like and you aren't going to get any support from VMWare with the free version.
If they were Windows 2012 servers I would probably suggest going with HyperV. I think it is a little easier of a jump for those familiar with Windows than going to ESXi. You can get a standalone HyperV, but if you have no experience with Windows Server Core it will be a steep learning curve doing the initial setup.
But before you can do that you need a properly setup ESXi Hypervisor and from the questions you are asking about ESXi VMWare Workstation I have a feeling you are missing some core parts. Mostly because you don't want VMWare Workstation. You want ESXi on the server and vSphere client on your workstation to manage it.
I'm all for trying things on your own, but if this is for a production server I'd suggest hiring someone. Migrations are filled with little gotcha's and the like and you aren't going to get any support from VMWare with the free version.
If they were Windows 2012 servers I would probably suggest going with HyperV. I think it is a little easier of a jump for those familiar with Windows than going to ESXi. You can get a standalone HyperV, but if you have no experience with Windows Server Core it will be a steep learning curve doing the initial setup.