The easiest would be a Linux solution - something like this one:
https://www.olimex.com/Products/SOM/STMP1/The STM32MP157 has OpenGLES Graphic Acceleration, the 151 and 153 only have simple framebuffers. You can use QT, wxWidgets, GTK,... for your application.
The LCD screens are standard dumb LVDS displays without memory or anything else - just the driver chips for the glass. The GPU inside the processor does all the work. These displays are available in all sizes and resolutions up to full hd. Look in the processors manual what the maximum resolutions and pixel clocks are.
These LCD scrrens are also available with touch support.
Some folks will recommend Raspberry PIs. These boards have the huge disadvantage that they can't drive standard LVDS displays. You are limited to the DSI displays they offer.
If you prefer microcontroller platforms - yes, there are some. But software development is more difficult on these platforms. Linux apps can be developed on a PC and ported to the embedded board later on.
fchk