SW part looks fine to me. If you find Veeam to be too expensive, send me a message and we can find a suitable cheaper alternative (VMcom, Nakivo, ...).
As for the HW part, I am not sure this is going to work. D3600 is a directly attached storage (DAS) designed to expand capacity of a single server. Even if you manage to cable-in two hosts, you probably won't be able to use it as shared storage and the solution will not be supported by VMware.
From HPE portfolio, you might want to take a look at MSA. I'm sure the HPE storage guys can help you with this. You can still go with SAS for up to 4 hosts.