Compare VMware vSphere Editions | United States
Please open above URL and scroll it down to find vSphere Essentials or Essentials Plus kit.
Any one out of those two will fulfil your requirements.
Let's say, you go for vSphere Essentials kit, that will let you license upto 3 ESXi hosts (2 sockets per host, unlimited cores)
that also comes along vCenter Essentials license, for central management.