Speaking from the point of a Jack Russel Terrier owner, they are little Houdini's.
You would need very very good secure yard.
As puppies, I have found they are a lot more nippy than the average pup.
Roly was never a really playful dog either, on walks he was more interested on smelling things. I could never encourage him to play.
That said, I am also, as a lot of my fellow forumers, a huge fan of shelters. They're are so many gorgeous dogs that will suit your lifestyle.
Im so sure that there will be some JRTS there for you.