All the ones I tried looking on Amazon look questionable and low quality. I rather have one built into a folding case than a standalone bluetooth keyboard too.
http://www.amazon.com/s/?_encoding=...4+ke,aps&rh=i:aps,k:tab pro 8.4 keyboard case
http://www.amazon.com/s/?_encoding=...4+ke,aps&rh=i:aps,k:tab pro 8.4 keyboard case