How to get design onto leather shoes?

[orora25.livejournal.com]

I adore these shoes, but I refuse to pay $70 for them. I was thinking about altering a pair of plain black leather pumps I already have (and never wear), but I'm not sure how to get a kitty design onto the shoes. Would acrylic paint work? Is there another medium that would work better? Can I stencil them? Would the paint crack? Should I seal them somehow? Any ideas are much appreciated.