Yes sir, a lot to consider . What I would recommend is take the pure breed gyp back to a pure bred dog with the traits you are looking for and start there.
x2...if she is scatter bred even though she is bmc then there will be lots of variability even when breeding her to a pure bmc...but you have a better chance of getting what you want going that route...like already mentioned...breed to a male that has all the qualities you like and if he is tight bred the better...