Hi Gabriel
I’m not sure if you could get a serial touch screen easily, however, I do remember seeing 2.8"resistive touchscreens at very low costs. Off hand I do not have any links, but, I shall post some soon.
Best regards
Jerson
1 - dnatechindia.com/SPECIALS/TouchScreen.html
2 - aliexpress.com/item/2-8-Mobi … 50874.html
3 - aliexpress.com/item/2-8-Touc … 08285.html
4 - adafruit.com/products/333
is what I got till now