Reddit mentions of Romance of the Three Kingdoms

As noted, it's available free online, but if you wanna buy a Kindle version direct from Amazon (I did), check this: https://www.amazon.com/Romance-Three-Kingdoms-Luo-Guanzhong-ebook/dp/B019PLY87K/

At least in terms of readability, it's been sufficing just fine. 82% through, gonna replay the DW8XL story mode after I finish up in order to fascinate myself w/ all the little alterations - and accuracies.

It looks like it's not maintained these days, but there's an online resource cached by Google that had annotations by readers that helped explain things. It's not exactly pretty given the current state of the website but:

http://www.threekingdoms.com

EDIT: Alternatively, the Kindle ebook version is $2 on Amazon. I grabbed it and have scrolled through. Tons of names are casually thrown around and some are different from the Koei spellings (i.e. Zhang Jiao is Zhang Jue in the version I have), but it's 4000 pages of reading for a couple bucks.

ROTK Kindle