I saw this and thought I'd offer my 2 cents, as I've worked w/dogs my whole life, and always had at least 1 underfoot.
I'm gonna side with Kansaseq om this and say wait, but just a little.
Once you have this dog started on the training, til he's at least aware of what his task is, his job, then get another.
I had a really great experience when my husband & I got a puppy many yrs back in February, got him started w/housetraining & obedience, then in late May got another (as a rescue, not planned but I'm a softie)
Watching him get rewarded for the good behavior, and him watching her get disciplined, made for 2 really well behaved, socialized, fantastic dogs. In a sense, they helped train each other-the first dog was a male & ended up being my husband's sidekick, and the second was a female who was my little baby.
But dogs are pack animals, so if you were to get another too soon, I think it'd be hard for them to go do their own task, or keep them separate for very long.
Sorry for so long of a post!