Welcome to BPO.
I think the ideas above-the squirt bottle and the leash-are good. The noise of coins might scare the cat (as would the water if you aren't a good shot) more than the dogs. I used "leave it" or "no", with an occasionally water bottle squirt for Riley, my Saint, who likes to bark at the cats if they hiss at him. You basically need to establish that the cats are off limits. You may still have occasionally chase scenes or barking, but puppies can be taught to respect cats or, at least, to respect their people's rules about the cats.
I will stay off of my declawing soap box, but I will say this: Please, please keep that outdoor declawed cat indoors. Declawed cats do not have a good means of defense (including to defend themselves from your dogs), nor can they climb to get away from predators. They become sitting ducks, unless you have him/her in some sort of enclosure to keep him/her safe.