Thinking about adoption - need advice

[ALFIEMAC]

My husband and I are very fortunate to have twin boys, conceived via IVF who will be 4 years old at the end of May. Hardly a day goes by when I do not feel blessed to have them and cobsider myself very fortunate. That said, I would very much like to have another child and having had 3 x further IVF attempts since the birth of the boys we are now considering adoption. I will be 42 years old later this year and my husband will shortly be 40 - do you know whether we would be considered for adoption bearing in mind our ages and also what sort of age gap would there need to be between our boys and another child (I believe we would not be able to adopt a child older than our current children).
All I hear about are the downsides of adoption and the fact that so few children are readily "given up" for adoption and are in some way damaged. Does anyone know anything about adopting from abroad?
All advice much appreciated.

It took 18 months from initial enquiry about becoming adopters to the day when our 10 month old came home. Then another 4 months for the adoption to go through legally. I was 36.
We were advised to wait 18 months before making an application to adopt a second child.
Second time it took 1 year from application to our second child being placed again at 10 months old.
A friend I made at my adoption preparation class was 42 when she adopted her first ( 20 month old) and 45 when her 14 month old arrived.