They are still available.
Dell Optiplex 760 Desktop PC - Intel Core 2 Duo 3GHz, 4GB DDR2, 160GB SATA HDD, DVD-ROM, 8x USB 2.0, GigE, Win 10 Pro 64-bit, Refurbished - PC1-0850 at TigerDirect.com
You can also find a refurb and install an add in PP card.
Some older IBM laptops are on Ebay as well and they can come with a docking station. Those have PP cards in them too.
Then you can buy an Ethernet smooth stepper and virtually any PC with a network card can run with it.