second/third! rear driveshaft / damaged rear diff

clunking in slow reverse on the 04 at 168k miles. center support bearing on the rear driveshaft is bad. was already on my list because someone here says they need to be replaced at 150k miles. confirmed by my local independent.

so what else should i replace at the same time? guibo/flexdisc? maybe the whole driveshaft?

does anyone have experience with the dorman? video at the dorman site (https://www.dormanproducts.com/p-85836-936-597.aspx) says their u-joints are...

second/third! rear driveshaft / damaged rear diff