I totally agree with Goldenretrluver. Waiting until your current pup is a year is probably best. That way, your current pup will show you what kind of personality you'd be looking for in your second. Kai was always getting into trouble as a puppy but he's completely different now that he's grown. Dogs can change quite alot from 4 months to adults.

Now, when you do get your second one (whenever you decide is best), make sure you give special attention time with each dog and keep your lab pup's schedule consistant.

As for breed suggestions, anything would work. Find out what kind of personality your dog has and ask experienced dog people what they think..dog trainers, vets, dog crazy people (like us) . My suggestion though, try your best to rescue. It may be better with an adult as you'd know what you're getting.