TAP Plastics have several sizes of mixing cups. They also carry such things as sheet mylar (I didn't like reusing the mylar tape supplied with the Pygmy kit), plastic syringes, tongue depressors for mixing, squeegies, etc. I have local stores, but I think they also have a web catalog. If they don't have a store near you, maybe there is another similar plastics supplier for this sort of miscellaneous handy stuff.

Personally I find that, once the pumps are burped, they work well. I follow Rob Mack's advice and marked the plungers so that I can deliver 1/2 and 1/4 strokes for smaller batches and find this works quite satisfactorily. So far anyway. I have complete faith in my unlimited ability to screw things up royally from time to time.