Jumping up is an easy thing to sort.
I think for your situation older dog is the better fit. He is ready to start training which will in itself help forge the bond between you as a ‘pack’, and will still need a fair bit of activity for the next three months, but this can be done in bursts of play and he will learn your routine pretty quickly, and then sleep during your work slots.
Jumping is fixed by turning your back on him and ignoring him when he does it, and then turn back when all four paws back on the ground. Angus now gets so excited but is near religious in his keeping paws on the ground. Dogs have been bred to crave our attention so denying it to them is the best sort of rebuke, telling the dog off/shouting/”NO”, while useful sometimes, is still a form of attention so best used minimally and not for stuff like this. You will need to make sure the kids stick to it as well. We didn’t enforce a strict jumping up ban with last dog (Cos i was a kid thought it fun) and it was a pain – needs to be 100%!
But he looks a fine hound, short glossy coat so not as mucky as a long haired fluffy beast…