I recently did a search for something similar without much success. I would recommend you have it custom fabricated. Chrome tubbing is easy to come by if that finish is acceptable to you. If not, you could buy a inexpensive towel bar in your finish of choice and take it apart so that you can incorporate the bar in the the shelf unit you are considering. If this is all too much to consider, I recommend you look to Ginger or Franklin Brass for ready made all metal models.

This is an old thread but seeing as this is unanswered for people who are searching...just saw some of these on Signature Hardware.