I strongly disagree with getting two as do most trainers. If one is a barker, he will teach the other one to bark and then you will have double the problem. Training two puppies is very challenging, especially if you work full time as they need lots of separate training.
Two Puppies or One? - VeterinaryPartner.com - a VIN company!
As far as one puppy, a lot will depend on her personality. Some dogs are barkers, some are not. Make sure you don't get a puppy until she is at least 12 weeks old and very well socialized.
How sound proof is your apartment? How is your downstairs neighbor? Does she like pets (hopefully have one of her own) or do you think she is a complainer? An animal lover will be more understanding of occasional barking in the beginning while your puppy adjusts. Of course, no one wants to listen to a dog bark all day long.
It's always risky to have a dog in an apartment as they are always conditional. If they disturb the neighbors, you will have to either move or rehome the dog.