VMware has just released a new KB90343: What You Can (and Cannot) Change in a vSAN ESA ReadyNode™. For those looking to utilize the new vSAN 8 Express Storage Architecture (ESA) this is a great resource that outlines what components in a vSAN ESA ReadyNode™ can be changed. As outlined in KB90343 both CPU, Memory, Storage Device, NIC and Boot Device can all be changed from the defaults — check the KB for details. The vSAN ESA VCG is also available, albeit with a small number for vendors for the time being.
The KB also includes a very handy vSAN ESA ReadyNode™ FAQ which includes advice specific device requirements and minimum network requirements.
An updated vSAN Sizer that supports ESA is also under development, and should be available soon.