And I do second the rescue dog option. The upside of that is that:
a) the foster carers know the dog well and can tell you a lot about them, including if they would cope with being alone during the day and how much excercise they need. They can tell you about their bad habits and how hard it may be to train them out of those (mine was a jumper - fairly easy behaviour to reverse). They can definitely tell you if they are barkers. Etc.
b) you can get a (slightly) older dog. Puppies are very cute but they are more work than an older dog and most will struggle with being left for 8 hours a day.
c) you get to take the dog on trial for a couple of weeks and return them if you discover that it really won't work.
I'm up to my second rescue dog and have never regretted my choice.