There's ones with the older/unresponsive designs -
IBM Model M13
IBM Model M4-1
IBM Japan 5576-C01
Unicomp On-The-Stick
Unicomp Endurapro
Ones with Trackpoint III/IV -
IBM Spacesaver II
Various iterations external Ultranav keyboard
There are a few out there with non-IBM trackpoints, but I dont think they're any good.