The new FAS8040 single and dual controller configurations come in one chassis only.
I believe that this is not full HA best practices, and may not supply best uptime in case of chassis hardware failure.
(for example, we had, last week, a FAN failure that was caused due to sensor problem inside the chassis. The replacement required full downtime. Since we have 3240HA system with 2 chassis, there was no downtime to our clients).
The only solution I can think of is metro cluster. But this will require x2 disks (and controllers).
Please advise or share with me your input.