Alec,
The type of handle is called "one piece." More generally, any metal handle might meet your desires. A lot of makers, Japanese, and European manufacture them.
Talk about bizarre handles. Make very sure you like Chroma's handles a lot before buying them. Otherwise, they're nowhere near as good as Global. The alloy they're made from, 301, has a really lousy reputation. From the steel faq: "Not a knife steel. Used in low end stainless knives. Avoid." They are listed as having 16% to 18% chromium and should be pretty darn stainless, though. To be avoided, unless that is, you're gaga over the handle and general design and don't care how quickly the knives go dull or how often they need to be steeled.
Other than for special purposes when something like a "chef de chef" or meat cleaver is necessary -- cracking lobsters, splitting raw chickens, and so on. "Sharp" is better by far than "heavy" for cutting dense materials.
That said, the sharpest knife most people use is a brand-new one, right out of the box. In fact, that's usually not very sharp; and almost never anywhere near as sharp as you can get a decent Japanese knife -- including Global, by the way, which actually do come fairly well sharpened.
No knife stays sharp forever. With normal home use, the longest a knife with a very long lasting edge can stay what I think of as usably sharp without being sharpened (and not a "sharpening steel)" is less than six months. With a normal knife like a Global, about half that; if you treat it right and you're lucky.
The degree to which a knife is stainless, depends mostly on the amount of chromium in the blade steel. Besides making the alloy highly corrosion resistant, a higher mass of chromium usually leads to all sorts of undesirable sharpening and edge holding characteristics.
Global's CroMoVa is actually pretty extraordinary in that it's as good as it is, considering how much chromium it's got.
But, how realistic is it to ask you to keep a knife sharp?
I'm not sure how you ruined the Katana(s). At 14% chromium, they should have been able to shrug off the amount of abuse you described. Which leads to the conclusion, that you got a bad knife to begin with, gave it a harder time than leaving it overnight in the sink once or twice, or both.
Since you seemed to like the Katana so much, the first thing to do is see if Calphalon will replace the knife for a manufacturer's defect. I can't speak for them, but knives being what they are, many manufacturers do NOT require proof of purchase, if that's worrying you.
Wusthof has a line with most of the characteristics you were asking about, called Culinar. It's in the same price range as Global, a slightly larger handle (although not as good in my opinion), and significantly heavier. In addition, the chef's knives have what's called "a German profile," which you might like. They're stainless (15% chromium) to the same degree almost all German knives are -- very similar to what the Katana is supposed to be.
Globals are basically an idea whose time has passed. People mostly bought them for their looks and the incredible hype that surrounded Japanese knives when they first hit the market in a big way. Unfortunately, no knife could survive the lack of sharpening and basic maintenance that most purchasers gave them. Not to repeat myself, but nothing stays sharp forever.
That said, they're actually very good knives and should suit your needs well until they get dull. Although not quite as corrosion resistant that's true for Katanas and Wusthofs too. There are much better knives for the price than those three lines, though.
Considering the level of care you're willing to give a knife, you might also want to think about buying something relatively inexpensive like a Forschner Fibrox and a cheap, easy to use sharpener that will keep your knife usefully sharp but won't do much for longevity.
The best alternative is taking better care of your tools.
BDL