Here are some additional links for Japanese manufactured knives.
Cutlery and More has a wide selection of knives and all kinds of cooking stuff. I've used them several times and have found them fast and honest. They made a mistake on one of my orders, plus were messed up by Pay Pal, they not only corrected their error without any BS, they took care of Pay Pal's by shipping my order on trust. At any rate, I've included them here for their selection of MAC -- the working chef's choice. No BS, no legend of Samurai. Light, sharp, well finished knives at a fair price -- value throughout all four of their lines. They also sell Shuns. I'm not a fan of Shun, personally. Partly because I'm left handed and don't believe someone else's kitchen knife should be dangerous to me, or vice versa; and partly because I feel a lot of money goes into cosmetics. Still, a lot of people really like them.
Mac Knives - Your Mac Knife Store, Full Mac Knife Selection, MAC Japanese Knives, chef knife
The next three,are the nucleus of e-tailers for U.S. fans of Japanese kitchen cutlery.
The Epicurean Edge: Japanese and European professional chefs knivesProducts Japanese Knife,Japanese Kitchen Knife,Japanese Chef's Knives.ComKorin - Fine Japanese Tableware and Chef Knives
The link RSteve posted is for an e-tailer who belongs in this group, too. At one time it was associated with Japanese Chef Knife.com, but I'm not sure if there's still a relationship. Fred of Fred's Cutlery Forum would know. If you care.
I've been thinking about what I wrote to you, and I'm not so sure that I'd switch to Japanese knives over French carbons. My knives handle so well, and suit me to a "T." What can I say?
If I were shopping now, I'd only consider certain Japanese blade profiles, anyway. Gyuto, Sujihiki and Petty. Gyuto is a French (as opposed to German) profile Chef's knife as far as the edge and belly go -- but the Japanese like to drop their point a little more, and a little later along the spine. Japanese forged gyuto are substantially thinner and lighter than German knives -- but not much more than French carbons. Japanese stamped gyuto are lighter still.
Speaking of stamped vs forged -- get over your old fashioned prejudices if you still have them. Good stamped are every bit as good as good forged these days.
Sujihikis are very similar to French slicers -- which are very similar to German slicers. The principal difference between French and German profiles is not the blade itself, but the bolster. Japanese knives are made without bolsters. Although most better Wester styled Japanese knives have a half-bolster styled ferrule sintered to the blade, and a naked heel. Several German manufacturers are copying the pattern by the way, by grinding down the lower part of their bolsters. E.g., Wustohof Ikon and Le Cordon Bleu. Anyway, the suji is a familiar pattern very useful for Western cooking.
Pettys (petties?) are just spear-point paring knives along very similar lines to a European slicer or "utility."
I don't like Japanese boning knives -- of which there are several shapes and sizes. I also don't care for their principal fish filleting knife, the deba, either. These knives are balanced, profiled and styled very differently than western knives designed for the same purposed. Japanese pattern boning knives like honesuke and garasuke have a very wide profile, and a dropped point, as opposed to the long narrow profile and up-rounded point of a European pattern. The western deba is part of a two knife system for filleting, skinning and slicing fish. The deba is a heavy, stiff, and wide knife shaped a lot like a French chef's, but deeper, and is used for the filleting and cutting through the spine to take the head. They use a suji for skining and slicing. Frankly I prefer the Euro style alternatives. Maybe it's just what I'm used to.
And when it comes to real specialty knives that don't get used very often -- they're hard to find from Japanese manufacturers, and when you can they're too expensive. I figure that's why God invented F. Dick and Forschner.
You'd asked about steel hardness, and I didn't answer. Anything under 55 HRC (Rockwell scale) is too soft for a modern knife. Anything over 60 is extremely hard -- which may be good or bad depending on the steel's resistance to chipping and your ability to sharpen a knife that hard. Because hard or not, they get dull. For a well designed knife, figure each 2 point HRC nets you about 25% more time between sharpenings. If your knives are over 58 HRC, you're pretty much committed to water (ceramic) or diamond stones. Everything else takes too long.
The good, old, carbon Sabs act a little harder than my newer Elephant carbons which are rated at 55-56 HRC. However, knives can be very idiosyncratic. The blade on my 7" Nogent slicer is at least 70 years old, but it absolutely kicks my @$$ on the stones. My other Nogents, sourced at more or less the same time from the same supplier sharpen very easily.
When I was working the line in the early seventies, I sharpened my K Sab carbon chef's (still got it!) every work week. If I were using a really good Japanese knife, that would be about every 2-1/2 weeks. By the way, a carbon Sab will easily take and hold a very Japanese "V" single bevel of ~15 deg. It may possibly
require a little more steeling between edges, but that's hard to say because I steel more often than required. In fact, every time I take a knife out of the block to compensate for my wife's never touching the steel.
If I were choosing a new chef's, I'd choose between the Hiromoto AS, and the Ryusen Blazen as the best, no BS, every penny goes to making the knife better, knives. Actually, I'd go Hirmomoto, but you might not like the fact that the composite, stainless-carbon blade uses carbon steel for the edge.
FWIW, If I were buying new stones, I'd go Shapton Pro, plus a Hand American borosilicate-glass "steel." Seriously man, when you think about this, don't forget to seriously consider what you're going to do about sharpening. A good set of stones with four surfaces is at least as expensive as a good knife.
BDL