i dont even know what kind of motors to buy:(
OK, that's good information: you are not dealing with an existing vending machine that you are trying to control, so you can choose the kind of motors you want. In that case, I would stay away from AC motors and stick with low voltage DC motors (assuming that they will have enough power for what you want to do.)
The circuit you have will work for DC motors, but a MOSFET as described earlier would probably be better. Your relay circuit would also work with AC motors, except that you would want to completely isolate the AC power paths from the DC control paths. As it is drawn now, the motors use the same power supply as the Arduino, you would need to make sure there is no connection from the AC motor supply to the DC Arduino supply.
You are much better off (and much safer) sticking with DC motors. Do you need to actually make a working vending machine? In that case, the speed and power of the motors are important. Or do you just need to make a simulation where pressing a button causes a motor to spin for a few seconds, but that motor isn't really hooked up to something? In that case, just about any small motor would work.