The Credit Tokens seemed to work out well at the last game locally.

But I do have a question: How many tokens should be made up for 18 players?

Also, is the sheet (the PNG file) supposed to be an odd paper size? It doesn't fit well on a 8.5x11" I'm guessing metric and/or european sized paper?

It's made for A4 size, or rather, A4 size - the margins of my printer. If you want a letter sized sheet, you got the source file right there beside it at my server...
One printed sheet is enough for 4 players (I think).