It looks to me like the stampworks kit contains a bunch of things that you probably already have. You might consider getting the parallax educational parts+text kits and make them work on both your existing stamp and Arudino.
Currently, parallax offers a bunch of educational material aimed at "microcontroller education", while Arduino material is more aimed at "doing things without microcontroller education." I don't think anyone has the sort of kit+instructions that you are looking for to go with arduino; you can either put together similar collections of parts and experiment on your own, or use the parallax kits...
Figuring out how to follow the parallax educational texts using arduino hardware is likely to be VERY educational!