Okay
On the lower surface we will have the mechanical device, which will be a controlled Catapult which will throw the load onto the upper surface into device two. (the electrical one)
Thus we need some motors to drive a device like theirs in the linked video below to move the load about without much of a hastle
Cheers Trent
Edit
If its easier i want some motors to drive a remote control car weighing, 6kg