I think the most important thing when getting another dog, is to make sure the two dogs get along before you adopt the second dog.
When I fostered dogs, I would always exercise my dog for at least an hour before taking him to meet the new dog. He was much more relaxed and calm without any excess energy. If you don't exercise your dog prior to meeting your new dog, the excess energy maybe expressed via dominance or aggression - this more likely to happen if you have to meet the new dog at the shelter, which is such a stressful place, so it's good to have your dog tired and relaxed before going there.
You want to find a dog who your dog is totally relaxed around, and doesn't show any 'iffy' behaviours, such as uncertainty, dominance, etc. Not all dogs will get along perfectly together, so you may have to meet a number of dogs before meeting the right dog for your current dog. One of my foster dogs went to a family who had been looking for the right dog for about a year.
As others have said, costs are definitely the biggest con to getting a second dog. Your dog should be receiving yearly vaccinations, monthly flea, tick and mite treatment, worming treatment every 3 months, bedding, grooming equipment, food, toys, collars, leashes, ID tags, registration... Dogs are expensive, and that price can double with a second dog. Definitely consider pet insurance.
Also, it's very important to make sure you have the time to take on a second dog. I was going to adopt a second dog to keep my boy company, but one dog is all I have time for at the moment. My dog is absolutely everything to me, so I put a lot of time and effort into him, and I just don't think I can put the same amount of time and effort into another dog. So I'm sticking with one for a few more years!
As for fur, the answer to all your concerns is a Furminator. They are amazing. When my sisters and I meet at my dad's place (generally on a daily basis) we have 5 dogs in one tiny house. All of the dogs get groomed with a Furminator at least once a week, and there is no hair anywhere in the house. They are amazing! I couldn't recommend them enough!
For the pong factor, keep your dogs on a high quality diet. Make sure they're being exercised daily, and aren't eating more than they need to. That along with Furminating, and a bath every few months should do the trick. Again, we do this with the 5 dogs, and none smell at all.