I recently found this post with 290 pixel fonts, and I made a quick processing sketch to convert the files to 320*200 png images which can then easily be converted to PI1 here. If I were more skilled I would've made a tool that converts directly to PI1 but eh, I did what I could... Still thought it might be worth sharing.
The sketch creates an image with all the provided characters in ASCII order, first as 8*8 tiles, then zoomed x2 (then junk text), like so:
The processing "app" looks like this:
Commands:
UP/DOWN arrows: browse the fonts list
LEFT arrow: display in the 320*200 screen.
S: save PNG (to the sketch directory).
Since I made this very quickly and didn't mean to share at first, there is at least one "bug":
When saving, the name of the PNG file will be that of the highlighted font in the browser, which can be different from the one displayed if you have pressed UP or DOWN after LEFT, so save right after pressing LEFT to avoid misnaming.
I'm uploading the processing sketch and the fonts. If you don't use processing you can still check the fonts there (very cool), ask for a PI1 in this thread and I'll upload it. You can even ask for a specific text.

Oh, and there is a .txt with credits when known.
Hope that's useful to somebody else!
Yann