Driving a wagon on wheels

Hi, I have a project in mind but i don´t know if its feasible with the "arduino start kit". I¨m a novice when it comes to both programming and circuit-building. I need to be able to pull and push a 20 kg wagon, forwards and backwards, at least 20 cm (8 inches). I also need to be able to control the speed of the wagon. Its supposed to be a "rhythmical and smooth", ongoing movement. Is it possible to attach a rope on each side of the wagon, use a motor to pull on the rope in one direction until the motor shuts off and a second motor, on the other side of the wagon starts pulling the same amount of rope? If not is there any other place where i can buy equipment to be able to realize the project? I've also thought about putting some sort of pushing and pulling machine on one side of the wagon. Is there any way to control such a device with your equipment?

I'm really grateful for your help!

/Karl

Use a large motor that slowly rotates a disk 20 cm in diameter.

At the edge of the outer face of this disk, attach a rod (using a bearing), which will then push and pull the wagon back and forth.

How you control the speed will depend on the characteristics of the required motor.

Thanks you for the quick response. I guess I've made things to complicated. Ill start googling equipment:)