DO NOT GET YOUR CAT DECLAWED. A lot of vets won't even do that because it affects the cat's personality and if the cat did by chance get out, it couldn't defend itself.
Don't get the scratching posts that are just carpeting wrapped around a post, get the sisal kind, it's like a rope and it's wrapped around a post. That is the closest you'll get to a tree and they last a long time.
Giving them something that looks like carpet will only tell them it's ok to scratch the carpet.
I've always had better luck with girls, because boys will spray, especially if you have more than one. Plus the girls tend to be more intelligent.