I camped on Kern by Isabella during a Death Valley motorcycle trip. Pretty cool to be right by the river, but not really any recs other than floating and fishing. Hiking was pretty non-existant, so we made up for it in debauchery.
If you can swing it, I would HIGHLY recommend Big Sur over the Kern! Beautiful views of the ocean, swimming holes, hiking, Jade Cove is kind of fun, abalone diving, overall a better time in my opinion!
Let me know if you have any questions.