Well...much the whole gambit of choices have been covered by posters and you can see the opinions are diverse and the preferences inconsistent.
Trying to decide which S&W to buy is like trying to order a meal when you're hungry from a restaurant menu with 100 choices. Asking others which handgun you should buy will just increase the confusion.
You've received so many opinions, all of them experienced, well considered, and valid. Never-the-less, I'll bet you aren't any closer to a decision now than when you first posted....
I believe everyone who has posted will agree you need to try to handle them all, shoot them all, then come to your own conclusions with what your preferences and needs are... It appears you have done much of that already, selecting K frames with your own good reasons.
Any of the K, L, or N frames mentioned are excellent guns and will serve you well. So will any of the barrel lengths. If you decide on a different choice later there are people waiting in line to purchase any of the guns you may choose... Go with the Mod. 66 6" you've mentioned and never look back. I can assure you it won't be your last purchase.....
JMHO
Trying to decide which S&W to buy is like trying to order a meal when you're hungry from a restaurant menu with 100 choices. Asking others which handgun you should buy will just increase the confusion.
You've received so many opinions, all of them experienced, well considered, and valid. Never-the-less, I'll bet you aren't any closer to a decision now than when you first posted....

I believe everyone who has posted will agree you need to try to handle them all, shoot them all, then come to your own conclusions with what your preferences and needs are... It appears you have done much of that already, selecting K frames with your own good reasons.
Any of the K, L, or N frames mentioned are excellent guns and will serve you well. So will any of the barrel lengths. If you decide on a different choice later there are people waiting in line to purchase any of the guns you may choose... Go with the Mod. 66 6" you've mentioned and never look back. I can assure you it won't be your last purchase.....

JMHO