I had four Jack Russell Terriers, its only recently that i have lost three of them within a year. The only bit of good advise to give you is :
Watch out if you get more than 1 x bitch. As you know dogs are pack animals and in every pack there must be a leader. That leader is 99% of the time a bitch.
Two or more bitches will fight for dominance and i mean fight. The worst case scenario is the strongest will fight until any threat to her are dead.
Where Dogs will fight over sex and getting 'the leg over', two or more bitches will fight to the death.
After 10 years of owning my dogs, i sought advise from a behaviouralist because one of my bitches would not tolerate the other 2 x bitches (she was fine with the dog though).
She asked me if through their life had i noticed things like??:
The dogs fighting to get through a door way,
Bullying at the dinnerplate,
The dogs fighting to seek an individuals attention.
I had noticed all of the above and she went on to tell me that if i had taken note when the dogs were pups, it could have been stopped. They were acting on behalf of dominance !!
The way I combatted it was to take the 'dominant' away from the others (she spent the last half of her life, away from the others and in my vehicle and with me at work)
This brought peace into my household after that.
If i hadnt bought my Wife her boxer dog, i wouldnt think twice about having multiple bitches again, but i would know the signs to look for now
I hope this helps m8