Dogs are social animals, they need to be with their families, and for them, that's their owners. Keeping one outside 24/7 is not good for them unless you can spend several hours per day out there with them.
I can understand the allergy problem but, can't the dogs be kept to certain rooms and, daily vacuuming and dusting be done in those rooms?
I wouldn't recommend any dog in a home where it can never be inside. I know dogs live that way but, I don't think those are good homes for those dogs.
We will be spending a lot of time devoted to him. Taking walks, training, chasing rabbits, and just general play time/bonding time.
We don't have a very large house, so we can't keep him in a certain portion of it especially if our other dog and him don't get along, but if the weather gets to hot/cold we will have him inside in a crate away from the other dog, and sometimes outside the crate still away from our other dog
As for dogs living outside, it all depends on the dog itself and what living situations the dog has outside. And as you said, how much time he spends with his owners also greatly matters. He will have good living conditions and will spend a lot of time with us every day. And I don't know if you have ever owned a rabbit dog, or if you hunt at all, but hunting dogs are kept outside a lot, since they normally have a lot of energy, as is needed for rabbit dogs. He's lived outside his whole puppy life anyway with his mom and siblings, so he's used to living outside.
Everyone has their own opinions about dogs living outside. One thing I don't do and don't think anyone should do is keep their dogs chained.