In my world, a Curve Tracer is a rarely needed instrument and with limited bench space, not worth the real estate it occupies. On the other hand, Power Supplies are always in use and therefore readily available. The bad news is this application requires a dual output GPIB controlled power supply with both current and voltage read back which significantly limits the choices of bench supplies.
This application supports the Agilent E3647a, but should be modifiable to support the E3648a,E3649a, and E3646a. However, for general purpose use, the E3647a is the best choice.
If nothing else, this might serve as an inspiration to use what you have to create a Curve Tracer. A couple of GPIB Power Supplies and a GPIB Multimeter to measure current just might do the trick.