Have you tried Innova's Evo cat food? I get it at www.petfooddirect.com,
and my three cats are better off than they've ever been. (I use the dry version, cheaper and easier for me.)
This food has NO grains (which can cause vomiting) and 50% protein, much more than Iams or other, possibly more expensive brands. And cats are "true" carnivores, they need this high protein.
This cat/kitten food is not all that expensive for me, even delivered, since it cuts down on vet bills, fur problems, hairballs, heath problems, vomiting, kitty-box cleaning, etc.
And I was surprised nobody else suggested this for clawing: A log. Cats seem to enjoy natural bark more than almost anything else, for clawing.
A simple, smallish, natural tree log, bark included, in their own area may satisfy their "clawing" need. Cheap! Worth a try, anyway.