How old is too old to adopt a newborn

First and formost I donot want to offend anyone who has adopted at the age range I am talking about. Totally not where I am headed wtih this, but I would like some imput.We have 5 children and I know I should be completly content to raise my 5, but I still feel such a desire to adopt again. Our youngest is 2 and our oldest is 16.For the longest time my husband was not on board with another adoption feeling like we were overwhelmed with where we were in life so I didnt feel it would ever be a reality.He has had a change of heart over this year and knows how badly I want to do this and would be in support of it if we can manage it financially.With the economy the way it is and some major unexpected expenses this year we have nothing to spare.He encourages me by saying "lets take a 1-2 years to save up again and then go for it. My concern is we will be 41/42 by then and I just dont know first of all if we would be considered by birthparents at that age AND if it would be fair to our child to be older when we brought them home.I know 40 is not old, but when I look at being late 50's when they graduate I think WOW!My parents were young when they had us kids and so they were always involved with our lives.We were young when we first started having kids it is just that we have spread them out over 16 years.I take my 2 year old to daycare and I am the oldest parent there. I worry about health issues that start to come about as we age and wonder if that is fair to a child.Maybe I am thinking too much but I would love to hear what you think.The idea of waiting 2 more years for another baby kills me, and yet I know we cant live beyond our means right now--I have 5 other children to think about!!Yes, we have considered other options of adopting an older child, but I crave the newborn baby thing and we just cant afford international adoption. Foster care is not an option because we are already at the 5 limit of children our state requires.Advice welcome and I hope I didnt offend any 40's out their adopting. I know age is just a number and I am not freaking out that I will soon be 40, I just want to do what is best for the baby!Thanks