I've started a simular project myself recently, I check on various parameters (reading level score, words per sentence, syllables per word, sentences per paragraph, average word length, average syllable count) and calculate the distance between 2 texts / authors using a simple euclidean distance.

I started out with the code provided on https://github.com/mac389/ToxTweet/blob/master/textanalyzer.... I use it in a private project, but the results are promising!