Barber halfs and quarters from the turn of the last century (around 1900 to 1917 or so) look identical except for size, and at least mine are very thin. THey have a very bold eagle on the 'tails' side that looks great on a mat. I think they're the most attractive silver coins you can find in he smaller denominations, and the thickness makes them ideal for Matrix. Three barber halves can be palmed in the same space as two liberty's. I believe they're called barber because that was the designers name.
they're a little harder to find, but I can get them from my local coin supplier for 2 to 4 times the face value value in very smooth, ready for smelting condition. I like gambling routines, and they have an 'old west' look to them that fits the plot of many of my routines, and they have a good audio ring to them also.