Server hardware for vmdk backups using VRanger

Hello,

We are trying to implement VRanger for backing our VMs (ESX 3.5) and would like to have it installed in a standalone server. Currently there are 36 VMs  which is likely to grow. Each VM has a C drive of 10GB that reside in SAN. We would want to back these vmdk files from SAN to the server where VRanger is installed.

Could anyone here suggest some options for a server to have this implemented? Since the size of the files would be around 400GB for now and much more later on, the hard drive speed needs to be considered too.

Thanks.