Hiya ladyluck.
I have 3 greys which have been introduced at different times. The eldest is 2 the middle one is 16 months and the baby has just turned a year old.
Having more than one grey has its good points as well as the negatives. There is no guarantee that the greys will get on together. I have two greys who are very bonded and inseperable but the middle grey took an instant dislike to the baby when he arrived so until you actually put the two together there is no way of knowing. I can have all three out together but they must be supervised at all time and they are learning to respect each others space.
I have seperate stands and they all have seperate cages, that is the way I will keep it as it works for me and the birds I have no plans of housing them together.
On the issue of bonding, I have had no problems at all! I have a close bond with all three and spend quality one on one time with each one on a daily basis, so I really wouldnt worry about the bonding at all just divide your attention equally between the two.
One thing you would have to closely monitor though is the baby being with an older grey. When you add a grey I have found them to do an awful lot of beaking to start off with this can look quite scary, I spoke to Dave007 about this after adding my second grey and found it was to determine the alpha bird. The boss of my three believe it or not is the middle grey!
I always do everything in order for the birds feeding etc from the eldest down to the youngest. Charlie my eldest is always treated as number 1 bird.
All three talk as well which is another question I get asked quite often with having more than one grey so it dosent affect their talking ability.
Do you know a lot about the new grey you are considering? Anything about his past? Has he been in contact with other birds at all? How did he react with them?
Please keep us posted on your decision wont you? If you get two there are lots of people here who will give great advice along the way and offer support.
Good luck:)