I wouldn't declaw a cat. There are ways to keep them from destroying the furniture, while keeping their toes intact.
- Adopt a pair of kittens: paired kids are more likely to play with each other than to play with your stuff. Lonely and bored kittens are more likely to engage in home improvement projects, while cats that have each other's company will tousle and wrestle and groom each other--instead of your couch.
- Scratching posts, everywhere. Give the cats an alternative that is more attractive than your leather sofa. Get a tall cat tree or several, depending on how large your space is. I got this Cat Craft Cat Tree at Wal-Mart for $35:
This one stands about 8' tall, and extends to accommodate ceilings up to 8'6". Attach dangling toys to the top, and watch your cats go crazy.
- Deterrents: line the corners of your furniture with Sticky Paws, which has a texture that cats hate. You don't have to leave it on forever. Once they get the idea that their paws are going to stick to whichever surface you put it on, they will give up on it and leave it alone. Bitter apple or citrus extract sprays also work.
- Claw-clipping: Get the cats used to having their claws trimmed when they are young. I do it once a week, whether they really need it or not. They are used to the routine, and it keeps their claws dull enough to prevent them hurting me when they climb over me, as well as prevent destruction of my new upholstered sofa.
- Play: You need to engage your cats' attention and energy, so it can be released in ways that won't destroy your property.
- REMOVE TEMPTATIONS:
Get the delicate items out of the cats' reach. If is valuable enough that you will be upset at the cat for breaking it, then protect it from the cats by putting it away.