A tough decision indeed, but sometimes a dog in need can't wait for the right time. That was the case when we rescued Mr., Purps and Pinks who were around 4-6 months old, we already had four dogs and Maddie (our Chessie) was 9 1/2 months old.
It was a crazy year with 7 dogs (4 of them 1 year or younger) but I still wouldn't trade it for anything.
Good luck with your decision.