Thanks, Dan, I forgot about chop dice cups. I have both wooden and leather dice cups, but I never bothered to get them "chopped". They are really (in shape) virtually handle-less mugs. However, I tend to reserve these for a dice stacking routine. In my stacking routine, based on the Mendoza routine, the final production of two jumbo dice and a can of 7-up is hard to beat.
In the context of dumpy chop cups, vanDokum and Johnson are the names that instantly come to mind. I chose the vanDokum cup because only Auke could make me the exact set that I wanted - 2 x 1" white baseballs with white stitching, 2 x 1" black baseballs with black stitching, 1 x 2" black baseball with black stitching, 1 x 2" white baseball with white stitching and 1 x 2" half white/half black baseball. The small balls are perfectly balanced for the cup. I think his chop cup is perfect!
Because I had a routine, the purchase from Auke was really just an upgrade of the props. My previous cup was manufactured by a local wood turner. I gave him the balls, a dumpy cup to model the shape, and a magnet. He then put the magnet in the wood blank and kept cutting the opening deeper and deeper until he got the right effect with the balls and cup. Then, he shaped the outside.
Jim Riser, of course, has superb chop cups, but his Riser/Loomis mini and larger Riser chop cup aren't dumpy style cups. As I mentioned before the key to a good chop cup is getting the balance between the cup holding the ball and the cup releasing the ball. You don't want to have to slam the cup down to release the ball; nor do you want to have to gently put the cup down to prevent the ball from jarring lose. So, the balls and the cups should be bought as a set, not separately.
Here's another ideaa. If you have a magnet concealed in your hand (eg in a ring), and you put a small magnet in the bill as you borrow it, you could use an ordinary cup for an "impromptu" chop cup. Even better, you could always just take a clear glass and wrap it with newspaper/napkin. It should be easy to just place a magnet on the base of the glass, as you are twisting/folding the cover. If you then put a bit of steel wool in the bill that you borrow, and have another one concealed in your pocket, you're home free. You'll have to experiment with the strength of magnet to place in the base, but it's a good impromptu method.
Also, don't limit yourself to using the chop cup principle for all the vanishes and appearances. That is, add some sleight of hand that doesn't use the magnet. So think of a one cup routine (with no magnet), and then use the magnet for a really impressive vanish or appearance.
Finally, as for routines, have a look at Jim Swain's writeup of Jenning's chop cup routine in "21st Century Magic" There are a lot of moves and ideas in there, and if I just had to pick one reference, that's probably the one I'd give (I'm not familiar with Ron Wilson's routine).
Sorry for the long post!
Bye for now