There's a good article here on how to facilitate a compatible relationship between your dogs and the new cat:
http://www.labadoption.org/linkpages...icles/Cats.pdf
Some info on introducing cats to each other:
http://www.catsinternational.org/art...roduction.html
I personally would be very hesitant to get a declawed cat in your situation. Even if none of your other pets
intend any harm, the new kitty doesn't know that and might feel very vulnerable. You could end up with a constantly anxious cat and all of the corresponding behaviour problems (inappropriate elimination, aggressiveness, hiding, etc). If you were able to adopt a cat from a foster home where s/he was already living with dogs and was comfortable in that environment, that would preferable. Either that or a cat with claws.
Do you have a tall cat condo or somewhere that the new kitty can escape to up high? Even with careful introductions, there may come a time when the cat just wants to observe the peons below without being bothered by them. I would also ensure that your dogs don't "go after" the cat, even if it's only to play. Keep them on a leash in the cat's presence until the cat is confident and comfortable, and the dogs aren't so interested in checking him/her out.