clustering which will give the continous working of VM and my core banking application

We are in to the banking sector. We have one virtual machine which is running with windows server 2008 having core banking application. As it is core banking application we don't want that virtual machine to be down. We have two ESxi host running.The possible options are like this

1) HA: If the host where my banking application running is down,the VM will restart on the next ESXi host. But here is there is a downtime of 15 Minutes.
2) FT: It is a good option, but when there is a application issue same will be replicate in the other VM also.

Is there any option to have clustering which will give the continous working of VM and my core banking application even the ESXi host failure