My advice is try and find a groomer who is used to grooming cockers for a show trim and who is willing to do what you want! Alternatively learn how to do it yourself.
If you clip short then the hair will all be the same length and therefore when it grows back it will be woollier. Is she spayed as this will also affect the coat. If you search under the grooming threads you will find lots of good info.
What you can try is threading an elastic band through the teeth of a comb and then as you comb it will pull out dead/fluffy hair. Coat Kings are also good.
Both my girls are spayed so I use a combination of coatking and thinning scissors.
If you post some photos you may get some more replies