Should we get a dog?

We've been seriously thinking about getting a dog. Dave is gone (not gone, but at work for 12+ hours a day and usually late into the evening and on weekends) a lot of the time and I would definitely love to have a happy, loving presence around when I would normally come home to an empty apartment and just to keep me company when I am home alone. I would also love to have a little dog to go walking/jogging with as the weather gets warmer and I continue to lose weight. But as much as we both want a dog around the house, we face some interesting obstacles...

• We live in an apartment so we want to make sure we get a breed that doesn't need a lot of room to run around or need too much exercise since we both work during the day
• Would a dog be ok hanging around the apartment while we are at work all day? Is it fair to the dog that we can't always be around?
  
• We do like to go camping and hiking during the summer so we want a breed that would enjoy and be able to physically handle those activities with us
• We don't know where we'll end up after Dave graduates with his PhD. Would it be a huge hassle to move out of the state or even to another country with a dog? Will it be harder to find another place to live in an unfamiliar location that accepts pets? If we do move, where would the dog stay when we come to visit our family in Colorado?
• How expensive would a dog really be? Food, toys, little outfits and vet visits I'm sure add up very quickly
  
• We know there is a need to adopt dogs in a shelter but because of the circumstances listed above we need to be more picky with the breed we choose to make sure we can provide a good home. Since we're so picky, should we even get a dog?
  

Obviously we are still working out the details and trying to decide whether or not this is a good time in our lives to get a dog. In the mean time, I enjoy looking at different breeds to see what might be good for us and I have fallen in love with Wee-chons; a mix of a West Highland White Terrier and a Bichon Frise. Check them out!