You might want to reconsider what you are looking for. It is true that dwarf retics can still get up to 14 ft. but super dwarves will grow to about 7 - 7 1/2 ft., and the genetic stripe is also a dwarf that grows to around 10 ft.
The problem you will run into is that these dwarves run several hundred dollars to $1600+ for the genetic stripes, and I don't feel that your limited experience with a ball python has you ready for a retic yet. I would suggest a carpet python or a red tail boa.