Companion Pet for 7 yr old Jack Russell

Question
Recently my 8 yr old cat passed away suddenly and I am
starting to think about adding a new pet to our family --
two adults and a 7 yr old, neutered male, Jack Russell
terrier named Chance.

Chance and the cat were not buddies but tolerated each other
and would ocassionally interact by chasing each other.  They
were not raised together but met as adults so it seemed like
after a couple of years in the same home they were still
pretty puzzled by the others actions.

As we are getting over the grief of no longer having the cat
in our family I have begun to research the possibility of
adding either a new cat or dog to our family.  I was
surprised to find in my reading that terriers are not known
for being good with feline companions--which explains some
of the previous interactions.  And since Chance is a VERY
territorial terrier I am wondering if I should give up on
the idea of a new cat and focus on a new dog/puppy.  
Whichever animal we choose to join our family we are
committed to making it work for Chance and our new pet.  
However, I am wondering if you have any additional practical
suggestions (other than the "take it slow" advice I have
seen elsewhere) and/or suggestions on pet
personalities/breeds that do well in a Jack Russell
household.

I would appreciate any advice you can provide!  Thanks!

Answer
Terriers,like any dog can get along just fine with other animals if they are used to them,I had a Scottish Terrier that was great with a Shiba Inu

If you are going to get a dog,a female would be best,and probably a Shi Tzu would be the best breed,as they tend to be very easy going,and pretty much get along with other animals,another choice would be a poodle,for the same reasons.Something else you can look into is going to the shelter talking to staff,and see if they have any laid back dogs-shi tzus are also common in shelters as well.You probably want to avoid other terriers.

Now if you are getting a cat,male or female of anyage will be ok-but do not declaw the cat,as he or she will need claws claws to defend itself,and also have a place where the cat can climb and hide from the dog