Getting a pal for your pup can have advantages but also disadvantages. I have an older spaniel that I put young dogs in with. He is very calm in kennel and very importantly will tolerate young pups/dogs. I have another spaniel who would not tolerate this. I use the older dog just to a point where the young dog has settled in his kennel and then gradually leave him longer and longer on his own as I do wish him to bond with this older dog. It can be very tempting to have two young dogs/pups together as they will play and keep each other company but the problems can arise when they are more interested in each other than you are difficult to overcome.
Being left alone in a kennel can be very stressful on a young dog and so he barks for your attention. He must learn two things. That his kennel is a safe place where you leave him for a while but will be coming back for him and that barking achieves nothing. This takes time, patience and a routine.
Take him out in the morning for his exercise. Home, feed him in his kennel give him a bone or toy to amuse himself (to me a bone is better as I have yet to see a dog toy that does not need a human to make it into a play thing) and leave him. Sit about in your garden/do some garden work so he knows you are there but occasionally go into the house for longer and longer periods so that you are out of sight. If he starts to bark, the second he does so "quiet" no need to shout just mean it. If he stops fine but if he does not stop and this is where some may disagree with me, I put on the angry man act rush over to the kennel repeating the word "quiet" and if needs be rattle the kennel door. Most go "oh sh!t" and run into the safety of their sleeping box. Peace will reign for a period but before he gets the courage to bark again go to him open the kennel door and let him out praising him but not over the top. Take him out for a short walk, back home and straight back into kennel. Keep repeating so that he learns quiet is good - barking is not good.
He will not fall out with you over showing him your displeasure. If his kennel is a warm, clean home he will quickly associate it with good things. Food, a safe place to sleep etc and will be quite happy to live there.
This needs you to train him to keep quiet in his kennel. Providing a kennel and leaving him in the hope he will stay quiet will not work.