Not sure if you're still looking for info, but others may be in the future too…
1) VMWare guest, 2 vCPU (mid-range AMD) and 4 GiB RAM. (These both seem to be sufficient so far)
2) We're using an iSCSI share on a large NAS. 2 TiB. (So far it's overkill, but we may expand the stuff we store eventually and we won't have to re-provision then)
3) Windows 2012R2 Data Center x64. (If I had to do it again I'd strongly consider Linux as I hear it's easier to setup CIFS on)