This is awesome! Please do try to find out how to get one's hands on these babies; they look fantastic. The dream resource would be a play in English, its translation in Cantonese and an audio recording of it being performed.
As for other sources of written Cantonese, there's Cantonese Wikipedia, and in recent years there have been a few novels published in written Cantonese, the most famous one being "男人唔可以窮" by 薛可正. As a novel, it's ok but not great. I'm about halfway through the first book (of two) right now, though I'm only reading sporadically. It's really great for us learners to have such a long text written by the same author, meaning we can get some quantity reading practice.
As for other sources of written Cantonese, there's Cantonese Wikipedia, and in recent years there have been a few novels published in written Cantonese, the most famous one being "男人唔可以窮" by 薛可正. As a novel, it's ok but not great. I'm about halfway through the first book (of two) right now, though I'm only reading sporadically. It's really great for us learners to have such a long text written by the same author, meaning we can get some quantity reading practice.