I think it is also important to take in consideration if you do manage to produce the hybrid offspring. If you do not get the disired outcome, what will you do with the offspring? I feel it is important to consider others, and the purity of both the GTP and BP line. If you did decide to sell these to the general public, even if you do specify to the buyer that this is a Crossed/hybrid animal, what is to stop them from selling that animal to the next buyer as a BP or GTP (depending on how it looks).
Just a thought, I am not against hybrids, I just think there is a certain responsibilty when "creating" these animals.