GPIB PC Compatability Question and Recommendations

Good Evening,

I have a client that needs PC upgrades for Eight (8) of their bench computers. These computers are pretty old and run on windows xp. A lot of the engineering equipment they use is pretty dated and almost everything is GPIB connected.

1. Each old PC has one older single-port NI GPIB PCI card.
2. The new PCs they ordered are running Windows 10 and they don't have a PCI slot on the motherboard, to directly use their old cards, just the newest PCI-E slot.

What do you think the best options are for upgrading 8 of these computers to be have connectivity with all 8 of these pieces of equipment via GPIB?

I'd like to consider costs as ordering 8 of the newest cards for this client might be a hard sale.

Here's what I've considered:

• USB-to-GPIB Adapter
• PCI-PCIe Riser Card/Adapter
• The NI Ethernet controller
  • i'm not sure exactly how expensive it will be as all 8 of the GPIB devices will need to be plugged into something else, assuming the controller itself can't handle 8 GPIB ports.
  • If there is another hard device to connect all of the GPIB connectors, what will the total cost look like compared to 8 standalone cards?

My concerns:

• Cost 
• Reliability (DoD Contract)
• Compatability