First, I have to ask the obvious. Why so many printers!? This is more of curiosity than professional assistance but, it may help point us in the right direction. Hardware, I would look at getting several servers (low to mid-range dell SMB servers should suffice, I can elaborate after more information from you) As far as an OS goes, VMWare ESXi would be a preferable choice for your venture. It's light and should allow plenty of virtual servers to suit your needs, greatly increasing efficiency.
I can point you toward recommend Dell units if I can have an idea of the loads your systems would be facing.