I agree with the current sentiment on breeding for smaller size. Being the only adult in my home comfortable with snakes(and in an area that I believe has a large snake and venomous prohibition) means that Retic's, Burm's and big Green Anacondas are not likely to ever be in my collection.
Now a Super Dwarf Retic, or a Tiger Python is entirely manageable, I just have to check on the local laws to see if they are acknowledged as separate animals.
What would be interesting though is a selective behaviour breeding program. Selectively breeding the least snappy juveniles. If you get a chance you should check out the Russian experiment on breeding foxes, one group for docile natures another for defensiveness. You could easily mistake the docile foxes for a common dog.
Edit: If you would like a larger BP I would seriously look at Angolans. There are only a few morphs atm so, you would be in on the ground floor and those bead-like scales are just so cool.