Which Virtual Appliance Download variant to use?

I'm running VMware vSphere 5, with ESXi 5 hosts. I want to run the Essential Business Edition to route between a vSwitch without NICs and a vSwitch with NICs.

This is what I'm presented with from the link in the E-mail:
utm-9.003-esx-v4-x64-smp.zip
utm-9.003-esx-v4-x86-smp.zip
utm-9.003-esx-v5-x64-smp.zip
utm-9.003-esx-v5-x86-smp.zip
utm-9.003-vmware-x64-smp.zip
utm-9.003-vmware-x86-smp.zip

I'd like to know how I should decide which download link I should use.

Does the "ESX" zip exclusively for ESX hosts, or does it include "ESXi" hosts? Is the "VMWARE" zip for VMware Workstation?

Should I use the x64 or the x86 zip?

Thanks.

Brian