Reddit mentions of Colloquia Personarum (Lingua Latina) (Latin Edition)

And this, this, and this, supplemental reading for chapters I-XXIV, I-XXV, and XXVI-XXXIV respectively.

Colloquia Personarum and Fabellae Latinae contain additional stories about the same characters featured in LLPSI Pars I, but with more emphasis on (and a more sympathetic portrayal of) side characters such as the doctor and the schoolteacher.

Fabulae Syrae is an adaptation of Greek and Roman myths from Ovid. I highly recommend it, as it contains more complex sentence structures, much more practice with the subjunctive in its various forms, and some very cool mythological stories that are fun to read and will come in handy if you want to understand works of literature and art that reference them.

The story of Familia Romana gets better as the book progresses. If you're stuck in the first third, I can see it being a slog at times. It also opens up quite a bit if you read the ancillary materials, which flesh out the characters and introduce various subplots with overlapping timelines and such. There are three:

Colloquia Personarum is a collection of readings meant to accompany the first 24 chapters of Familia Romana

Fabellae Latinae is a similar but open-source (nisi fallor) supplement with readings that correspond to the first 25 chapters of FR.

Fabulae Syrae is a collection of adapted myths of Ovid; it follows Colloquia Personarum and the readings correspond to the final ten or so chapters of FR.

You absolutely need Pars I: Familia Romana.

If you are an autodidact, you also need the Teachers' Materials & Answer Keys.

I would strongly suggest you get the Companion to Familia Romana, since it makes explicit all the inductive teaching from Familia Romana. If you let it become a crutch, then the course becomes "Just like Wheelock's, but with extra reading material." However, it's invaluable if you're banging your head against the wall, unable to figure out what something means or why something is done a certain way.

You should also get Fabellae Latinae for extra reading material, since it's a free download.

Since the whole point of the course is "lots of reading that teaches you inductively," I'd also get the Colloquia Personarum, which is extra reading material (like Fabellae Latinae) tied to each of the chapters in Familia Romana.

I did not get the extra book of exercises. Following the advice of Justin Slocum Bailey, I'm spending that time reading more.