If you are set on a declawed cat I would look for one that is already declawed. I know in our shelter there are always some that are. Otherwise research it and you might be horrified to discover what really occurs. We did have our first cats declawed and it was horrible. After that I researched it and wasn't happy about what I found out. Tigger and Belle have never scratched furniture and only carpeting once when they were locked in a room. Venus and Apollo are not so good, but I stopped clipping their nails, which I've started doing again.
I would go in as a family and really talk with the adoption person at the shelter. They really get to know the cats and know which cats would do better with young children (and the chaos that goes along with them

). We have a real busy household and our cats are fine with it for the most part, but some cats would not do well in this environment. Then visit with the cat(s), keeping in mind that some cats really have a hard time with shelter life and would be great in a household.
There was one persian cat that was SO scared in the shelter, even though she was housed with her brother. It was fun when she was on medication and I had to get her out of the hidey-hole she would stay in.

She went to a foster home and has done so much better.
There was another cat who was good at the beginning of his shelter life, but became more withdrawn. The heads of the shelter (husband/wife) decided to foster him for awhile, but was adamant that they were not going to adopt him since they had enough cats of their own. He really came out of his shell at their house and they fell in love with him--his adoption was on Wednesday.
I went on a tangent, didn't I?

There are so many cats that need homes and good for you for wanting to adopt a full grown cat!