The amount of room behind your stove will only be dictated by how far the plug sticks out from the receptacle that the electrical contractor placed in the wall too high. In other words, shove that puppy all the way back until it stops.
One thing on a serious note, make sure to install an anti-tip bracket. this is to keep your 4 year old from opening the oven door, pushing down on it, and dumping the large pot of boiling water down on himself.
The bracket is a piece of metal that screws to the floor and allows the range foot to slide under it to "clamp" it to the floor. It should cost less than $4 at most appliance stores and takes about 10 minutes to install. If you want the store to do it for you, I'd bet you could have it installed for less than $50.