I don't recommend doing a century in shorts that aren't already road tested, meaning shorts that you haven't already used for some long rides with success. If you use shorts that haven't been tested and they end up not working for you, you'll be lucky if you're just sore. You could get saddle sores that could easily keep you off your bike for a week or two.
As for the shorts themselves, everyone's different. Some people prefer minimal padding; some people need a lot. I need a bit less in the front and a bit more in the rear. It sort of depends on your anatomy. I will say that I have not had good luck with shorts that don't fit fairly snugly (not tight, just snug). The chamois moves around too much. For that reason, I prefer shorts that offers some compression.
The only short I'll wear at this point is the Sugoi RS. Between the material and the chamois, they just work for me. TE just recently started selling a new style by Louis Garneau shorts that I'm curious about. A few years ago, I was on the quest for some new shorts. I bought several from TE, including the Sugoi's on Susan's suggestion. Some definitely worked for me better than others.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher