Yep i agree.
All currently visible skill-values on a players profile page, should be able to be specifically searched for on the transfer market search page.
Height and potential are only ever useful for when you are searching for a player to train, and, as some other people have mentioned, when looking for a play-off specific player, experience/game shape are vital. Definately two thumbs up from me on this idea. and im sure this would not be too hard to implement.