I think we have got the perfect thing we looked for!
A company called "Shul Signs" which is manufacturing many kinds of signs for shuls etc. came out just a while ago with a "Page number Sign" that seems to be the sign we were looking for!!
You can see it here: https://www.shulsigns.com/page-number-sign-3.
they also have an option of 4 ...
No this is not possible. The Rambam (MT Gerushin 4:1) explains why electronic "ink" on a tablet doesn't work
A get may be written only with a substance that leaves a permanent
impression - e.g., ink, sikra, kumus, kankantum or the like. If,
however, [a get] is written with a substance that does not leave a
permanent impression - e.g., beverages, ...