Digital BW, The Print

I posted this in FM and was forwarded to post this question here in hopes someone can help.

I am using an Epson 2400 printer to print my B&W. The tonality is great and all but when 
I start using fine art paper like Hahlemuhle (even sent my B&W to a local print shop 
(Calypso, Inc. in Santa Cruz) that uses Epson 9800. 

I can clearly see banding when I use these fine art paper and you can see it when you hold 
the print close, like 1 to 2 feet away.  It's mighty bad, if I want to sell these as "fine art prints" 
when the banding is so apparent and I thought I'm alone when the print shop I used sent me 
prints with bands.

It's also most apparent in darker and flat toned areas.  I'm using ImagePrint 6.

The banding doesn't occur much on luster or gloss. Only fine art or watercolor papers.

Are there any good print shops out there that does great B&W prints? Any recommendations?

- Michael Soo
http://www.soophotography.com