Two chaos modules from Elby Designs to look at:
IF 120 Chaotica
IF 108 ChaQuO

I am using the IF 120. Very happy with it.
Many of the NLC look interesting to me as well and have though about adding one.

Also, there is a difference between chaos and random. Nicholas is asking for chaos and some of the suggestions above are for random. See An Introduction to Chaos Generators by Chris Meyer for an explanation:
https://www.elby-designs.com/webtek/panther/if108-chaquo/chaos-generators/chaos-generators.htm

All the best

P.S. Some of the Elby Design modules are deep so not skiff friendly.