I make my dog sit before I put the leash on... He gets excited and jumps and runs around but he knows I'm Not doing anything in till he sits calmly. So after about a minute of acting like he's on some type of drug, he sits calmly and I can hook him up. So if your dog knows how to sit, make him sit before you put the leash on, it may take a little while for him to realize that what he needs to do to go outside, but it could work.
To keep your dog from getting excited when you put their leash on for a walk you can try carrying the leash throughout the day so that it takes away the thought of going out. If you use the leash inside the house then the dogs will not think of it as a sign of going for a walk. Eventually they will not get excited over the leash.
My dog is the same way. All you need to do when your reaching down to put it on and they get all excited and start jumping and whining is to stand up and turn your back to them and continue this process every time they do it. If they behave give them a treat or pet them. This will show your pet your in charge and they go for a walk when you say so.