Mastodawn

I have TWO options for my comic book's size in paperback print that I think would work:

8.2'7''x11.69'' (21x29.7cm)
Edit, swapped size to
8.5''11'' (21.59x27.94)

BUT, first one is more expensive (premium color and paper) and I do not know if these sizes are available in all countries and I can't for the death of me find an answer.