Server recovery - lost disks

I am involved with the recovery of a Windows SBS 2011 server that has serious damage on the boot drive caused by a faulty disk. I've had Microsoft support looking at it most of today and looks like we need a full restore. The server has BE 2012 SBS version, but I can't access it as the server won't boot. I have the recent backups (on NAS box) but I do not have the original BE install disks, the BE serial Number or a BE recovery disk (I didn't set up the server)

Any downloadable ISO of BE that I can install in trial mode or something to access the backups? Alternatively is there any way to convert the existing backups to a virtual machine (again using a trail version)?

thanks