This is the ThinkPad X1 Carbon deal I'd buy today -- 64GB of RAM for less than $1,800

BE AWARE!!
Great article. I actually purchased your second recommendation without the touch screen and I went with 155H CPU & 32 gigs of RAM.
I received it in the mail yesterday and I wanted to point out that the manual it ships with specifically states that if you are replacing the nvme drive to ensure that it is only a single-sided drive. It states that the two-sided drives (black memory chips) are too thick and will not fit under the heat shield.

I love the idea of cherry picking the stock items that are not upgradable and then upgrading the others to save some money and get exact specs that you need, but this is definitely a limitation that everyone needs to be aware of.