Searching for Display Controllers & Development Boards

I'm working on an Arduino Due project with a 4.3" 480x272 touchscreen display (currently this one).

Up to this point I've been using Adafruit's RA8875 development board. This has been a great controller & breakout so far: I've been able to get double-buffering working for smooth animations, the built-in text rendering is fast and great for debugging, and the controller supports accelerated drawing of a variety of useful primitives (lines, triangles, rectangles, filled/unfilled, etc) but I'm running up against some hard limitations. In particular, it doesn't seem possible to render large custom fonts while maintaining 30 fps. There's enough onboard memory for a few pre-rendered characters, but not enough for all the characters I need (the digits 0-9, the percent symbol, and about 20 letters). I also haven't been able to get large character drawing to work fast enough when using "optimized" character drawing, like a line-by-line approach using the controller's accelerated line drawing.

This led me to the RA8876, for which BuyDisplay offers a development board with plentiful RAM (128Mbit). Unfortunately, this board is designed for 50-pin FPC displays, and while there seem to be 50-pin to 40-pin FPC adapters, I haven't found anything that will allow me to use my 4.3" 40-pin FPC display with this development board.

After that failure, I decided it'd be a good idea to broaden my search. My most successful approach for finding display controllers so far has been to search first for libraries on GitHub, then look into those controllers individually and search for breakout / development boards.

I feel like there might be a better way to find what I'm looking for, so I decided to ask the Arduino Forum for help.

I have two main questions:

  • What's the best way to search for display controller development boards that suite my needs?
  • Do you have any recommendations for specific display controllers?

My minimum requirements are as follows:

  • Must be able to double-buffer a 480x272 color display, and swap buffers fast enough for ~30fps animations.
  • Must support drawing large (~128 pixel height) fonts, either via enough RAM to buffer the pre-rendered characters, or by using a sufficiently fast interface to communicate with the Arduino Due (I'm not sure what this would be, SPI doesn't seem fast enough judging by Adafruit's RA8875 breakout).
  • Must not be absurdly expensive, certainly less than $100.
  • Additional features, like accelerated drawing primitives, scrolling, etc are a plus.