Sorry for the form email. I get a lot and didn't adjust it to your deba question.
OK, if you want a great upgrade to your current knife I would get this:http://www.chefknivestogo.com/kofubl2gy21e.html
Konosukes are really excellent knives, this particular one uses blue #2 steel and the moribashi deba is not as hefty so you can go up in size without the knife feeling like an ax in your hand. It would make a great fish knife and it holds an edge really well.
If you want to stick with a smaller one get the Doi. It's hand made in Sakai and it's an outstanding deba: http://www.chefknivestogo.com/doiblstde18.html
Kajiro Doi is an iconic blacksmith and retired last year. Takayuki stockpiled his knives for years so they still have them in stock for the time being. I hope to meet his son who is in his 60s when I visit his shop in Sakai in mid May this year.