[jmiller]

i can make one if you are seriously interested , getting data from card reader is not difficult but getting data from pinpad will be difficult if its encrypted so many people use overlays for pinpad, but i am not sure how serious you need, i dont charge anything, can help u for free if you want to experiment
what u will need to get started is to find specific model of gas pump which is mostly used and its internal working(limited to card transaction flow) like can you open the pump with master key and insert the device to communication channel or you want to go with overlays
its quite a task to start from scratch may be it will be easy for you to find already working pump skimmers but if you want to make one all you need is atmega+serial flash +Nrf +plastic overlays