I have dogs, but have no knowledge of beagles.
IMO puppy is best, rescue dogs have usually troubled backgrounds.
With a puppy, you set the groundrules, you do the training, you put in what you want from a dog and you get results. With an older rescue dog it takes longer to establish this rapport.
I do feel a little mean to say that, as i am a serious dog lover and cannot bare to think of all those lonely lovely dogs without a home. But, when you have children, you need to be 100% certain that you know what your letting yourself in for.
Of course the rehoming centre tell you as much as they can, but people are shrewd, the previous owners may not disclose everything to the rehomers, and therefore to you.
Id always be wary of a dog i didnt know.
Whereas, with my dogs who i have had both since pups (infact dog#2 is dog1s son), i trust wholeheartedly.
With regards to chewing and destruction, and if you get a pup, cage train it, so it is used to being left in a cage or crate (not as evil as it sounds, they actually like it - its den like). A mistake i made was not to do this and i have a serious chew problem with dog2. You probobly (very unlikely) be able to train an older dog into being caged.
Beagles have quite short hair though, so that will help with your houseproud nature, not so much hair means not so much malting and not so much doggy smell.
the kennel club hs lots of info on breeds, breeders, recommended reading, links etc.
Hope this helps