The "1784-PKTX" and "1784-PKTXD" are single and dual channel PCI DH+ cards. Of course, they will cost more than the computer they are plugged into, but, well, you know AB.
Oh, and they work fine under Windows 2000 and XP, but you need to do a bit of web-searching for the loadable driver if you are using anything but RSLinx.