IMO dogs are like children, you shouldn't have another child just so your current child has a playmate, you should have another child because your family just isn't complete with one and/or you truly want another child. Dogs aren't much different. I will say there's no way I would own 2 puppies at once. If you decide to get another dog, I would HIGHLY suggest getting on that's maybe 12-24 months old still young enough to run and play but out of the "puppy phase" so to speak. But IMO your efforts would be better put to use by doing formal training and more walks and playtime with the current puppy you have. Sounds like you have an untrained, pent up energy, wants to play puppy. Walking your pup 1-2 times a day for 30-45 minutes each time, doing some off leash free play in the back yard, and some structured training should go a LONG way to help with the unwanted behaviors and the hyperness.
I would not get another dog unless you and your family truly want another dog for your family not to occupy the dog you already have. I don't care how many dogs you have they will still want YOUR attention as well.
Tyson, white, 4 years, Boxer & Thor, 2 year old GSD
Tiger and Raven, kitties, 10 and 11 years
Erin flashy fawn, Lucas, Flashy Fawn, Boxer angels, RIP 11-29-10 and 8-22-07