Don't get one as company if he is barking/crying - you'll end up with twice the noise & twice the complaints from neighbours!!
I would say you need to address his issues first. How long is he left? How much exercise does he get - Dally's need a LOT of exercise. They were bred as coach dogs if my memory serves. As well as physical exercise they need mental stimulation.
If all his basic needs are being met sufficiently and he isn't being left for long hours, then there are ways of improving the situation for him. Providing entertainment (such as frozen Kongs, a radio left on) and avoiding external stimulation (are you by a busy street?)
The problem may be 'separation anxiety'. The way of dealing with this is usually to leave him for very short periods - seconds to begin with, gradually increasing the time - then returning and 'ignoring' him until he has settled, then calling him over for praise. If you google or wait until the more knowledgeable posters arrive, there is more to the 'action plan' than that.
Dally's can be highly strung - though the ones I've known have been OK but love people and need a very high level of stimulation. Big bouncy nutters with selective hearing.
Ultimately, it may be that yours is not an ideal home for this particular Dally - if you have to be out for long hours or can't meet his exercise requirements (though a dog walker calling in during the day could be a solution to both).In which case it might be best to consider what is best for the dog - and getting another dog isn't necessarily the best thing.