Outing to anyone who knows me, but I have a Jackshund - or Jack Russell X Dachshund as I stubbornly call him.
He was on his fourth owner (me) by 18 months. Some of that was fuckwittery by previous owners BUT I have to say that he was very hard work at that time.
When I say hard work, I mean anything less than 2 hours a day of walks, off lead, (3 hours was preferable) and I would live to regret it. This was definitely not fun when I was working full time 9-5, it was the depths of winter, and I (as a lone female) needed to get ddog walked after dark in a London park.
Anything young with a Jack Russell in it is basically like the Duracell bunny - the stamina is incredible, and it won't cope with 30-60 minutes a day until you hit dog middle age (and even then, you're looking at 60 minutes and preferably more).
He came with some behaviour issues which can be attributed to his early experiences (and the worst of it has been curbed, but not totally, any only with years of work and £££), but I also think they're genetically predisposed to it. Dachshunds tend to be a bit nervy and Jack Russells tend towards bravado and barking / snapping at things they're not fond of. As a result I have a dog that gets worried and then has a crack at the thing that worries him for the sake of it.
I love DDog dearly, but I'm not sure I'd have another... and I really couldn't recommend a Jack Russell X Anything for your situation. I'd be looking towards the companion breeds, rather than the working breeds which both JRTs and dachshunds are.