|MadSci Network: Physics|
I brought your question to one of the lab technicians in our Physics Department, who is most familiar with the equipment we use in teaching our students. He suggests that you look at Fluke multimeters, which tend to be smaller, more robust, and much less expensive than the Keithley meter you mentioned. We use Fluke model 75 in our introductory labs; they meet our needs and cost only about $170. For upper-level labs, we sometimes use the Fluke 187, a more accurate model which costs around $300.
The only issue that has arisen with the Fluke multimeters in our labs is that one of their fuses sometimes blows (especially when a student connects a circuit incorrectly) -- so be sure to have a supply of spare fuses handy.
Try the links in the MadSci Library for more information on Physics.