Ok, here you are; all came off of Amazon.com
1. 37mm DC Geared motor mounting bracket holder + 6mm hex coupling $5.32
2. RioRand mini 12V DC 60rpm high torque gear box eletric motor $11.99
3. 32P (4mm bore) 16T gear motor pinion gear $ 7.99
I use a tyco transformer that I had on an ho layout when I was a kid, it works fantastic!