We were in a similar situation with Peyton and Ty. Ty was almost a year old when we were told about Peyton, who was 15 months old. I was not completely ready to get another dog and wanted to wait until we found a bigger house with a fenced in yard (we were house hunting) then get Ty a sibling. Well, Dh and Dd decided that we should get Peyton anyways and they went and got her. The first few days were a bit rough, but those two have been inseparable since and really entertain each other. It really is easier with 2 and it hasn't interrupted Ty's training, we just add Peyton to the training. We just bought a house and close on it in 6 days-I really think that they will help each other get used to the new surroundings. I can honestly say that I will never have just one boxer again, two really is better! I say go for it!!