For my second, I used the ArmsReach Mini-cosleeper. It's about half the size of a pack in play so it takes up way less space in your room. Plus you can set it up high, flush to your bed, so you don't have to bend over to lay baby down every time.
Both my babies were 9+ pounds too. I was able to keep him in the cosleeper until he started rolling at about 4 months (then I moved him into a crib). If I had gotten the model that converted into a mini-crib (instead of just the cosleeper) I'm sure he could've stayed in it longer if needed. I believe the weight max was 22 lbs (for the model I had anyway), which he hit at about 6 months (BIG boy lol).
Also, the mini-cosleeper made nursing SOOO much easier...almost wish I would've had it with my first.
So to sum up...the mini's are a great space saver and great for nursing if you have the extra 100 bucks or so to spend.
If not, I'm sure you know he would also be fine in a swing or pack-n-play. Newborns are pretty great for being able to sleep anywhere :)
ETA: I should also note that I had the Graco pack-n-play with bassinet and newborn napper attachment with my first...it worked fine...just took up SO much room in our bedroom (and babies are so small lol).