Length:
21cm doesn't punish bad skills, but doesn't reward good ones either. 27cm rewards good skills, but it can be something of a bear learning to point (although you certainly can learn if you practice keeping the point in line with your wrist and elbow). 24cm (9-1/2") is a nice compromise; productive without being too demanding.
I prefer 27cm, but don't think that should sway you. We can talk about keeping the blade straight in another post if you like, and we should. It never hurts to tune up one's skilz.
Laminated aka "San-Mai" aka "Warikomi?" Or, "Monosteel?"
Japanese made blades are often made in three layers: Jigane-Hagane-Jigane. The cutting edge steel is the "hagane." The ad copy for laminated blades often talks about it in terms of sharpening or other positives for the user. In truth, all but one of the practical advantages go to the manufacturer. Because it's a surer method with fewer failures it's less expensive and manufactuer and the price advantage is passed on to the consumer. Also, it allows the manufacturers to use pattern-welded jigane to stick Damascus style patterns to the blade.
Most of the knives you've listed are san-mai. It's no big deal one way or the other, except insofar as you want good advice from me. San-mai knives have a sort of muted, "dead" feeling to me and a few other people. It's not a majority opinion, nor is it all that rare. There's no need to justify my feeling -- and I won't. But it's fair for you to know, and also that it has a lot to do with how much I don't know about many of the your chosen blades.
You have an interesting mix of wa and yo handled knives. Some of your choices come both ways, and you didn't specify.
With that out of the way...
JCK Hattori FH Gyuto wa and yo: Beautifully designed and made. Wonderful F&F. Very good handle, just a half step not as good as a MAC. Very nice profile, just a half step not as good as a Masamoto VG. Thin, easy to sharpen blade, good edge retention, easy maintenance. Hattori does the best VG-10 on the market, with no deburring issues.
Masamoto VG wa and yo: (You referred to it as the JCK Masamoto). Fantastic profile. With the exception of a Sabatier nothing feels as natural or as comfortable on the board. Excellent everything else, if not spectacular. You'll have to communicate with the seller before purchase because to avoid some QC issues.
JCK Original Kagayaki Aogami Super, wa: Don't know anything about this particular knife. My experiences with aogami san-mai weren't happy, but... it's not an unpopular construction and lots of people love it.
Kagayaki is JCK's house brand name, the knives are actually built OEM. The other Kagayakis are very high value, there's no reason to expect that this iteration is otherwise.
Ichimonji TKC, yo: It is no more, yet it lives. The knives are now sold by Chef Knives To Go (CK2G) as the Kikuichi TKC.
Another knife with which I have no personal experience (you're amazing that way, dude!). They have great buzz with a fantastic reputation for holding an edge. Everyone's comparing it very favorably to an Aritsugu "A," saying it's just as good without the issues.
For obvious reasons, I can't break the knife down the way I do with knives I know into profile, edge characteristics, feel and handle. Oh well.
Takeda Gyuto, wa: I don't like san-mai, and I don't like kuro-uchi (the rustic, black finish), and I don't like really flat profiles . But if I did, I'd like this knife a lot. Very thin, very well made. Easy to sharpen, gets sharp, holds an edge, doesn't wedge. The profile is well suited to "push cutting," but not quite as helpful to classic European technique as a Masamoto or a MAC. Still, it's not too exaggerated to prevent it from doing what you want.
There are other makers who do almost the same thing, almost as well, for less.
Kikuichi Gold Elite, yo: Kikuicihi gets a lot of mileage out of names. Judging by the price, you're referring to this one:
In addition to the san-mai, I don't care for tsuchime (hammered) or suminagashi ("damascus look") separately, and like them even less together. I know just enough about the handle and profile to say they're good, but not enough about the blade itself to comment. Expensive for a VG-10 san-mai sandwich. Taken together, the whole thing makes me too grumpy for you to trust.
Shun Elite, fusion: Excellent QC, F&F and US support. Made with SG2 in san-mai. As PM alloys go, SG2 is pretty good, at least it's not super-chippy; but all PMs, including SG2, are overpriced and over-hyped; and the extra hardening PM allows doesn't provide any practical advantages. If there's a worse gyuto profile, I don't know about it. Run away.
MAC Pro, yo: Chris warned you. I recommend this knife more often to more people looking for their first quality, Japanese made knife than any other. It's a little stiffer than the Masamoto VG, with a slightly better handle. Actually, the MAC handle has got to be the best of any western style handles, so "slightly better," is a big bouquet to both knives. The profile is a little wider and only slightly less good than the Masamoto's. It's edge characteristics (including "feel" on the stones), are identical to the Masamoto's, and I believe they're the same alloy. Very good F&F as Japanese knives go, usually good QC, a warranty and support which competes with Shun, and service and support that exceeds it (in case the QC fell through).
Side Trip to Sharpening:
Chris is right about the money. Bernal offers "Japanese Waterstone Sharpening Classes." Take one and see what you think. It can be done relatively inexpensively but from what we're learning about you and knives -- still going to cost a fortune.
Halfway to the Bottom Line:
If you're seriously interested in wa handles we should open the discussion to a few more knives. Still, if you want a good performer that's got a super Japanese, country look, and don't mind putting up with its idiosyncracies, you could do worse than the Takeda.
If you want a yo handled knife the best choices from a performance standpoint are the Hattori FH, Kikuichi TKC (at least by reputation), MAC Pro and Masamoto VG. They all have different things to offer.
Why don't you talk a little more about what you want in your knife?
BDL