Use an Arduino Mega (or e.g. compatible). It has a lot of I/O pins for your screens, lights, and buttons, and is very well supported by the Arduino IDE and community.
Buttons are wires with optional holes in them, so are compatible with every microcontroller on the planet.
You need to be more specific about what kind of LED screen you are planning on using. Are you thinking about seven-segment displays? 0.96" monochrome OLED? Or 4K HDMI?
Amazon. It's pretty cheap if you go with the "Arduino Compatible" boards. If you're making an actual product though probably best to try and buy official ones from someplace like Mouser.
the one Ben sells is $15 on Amazon
I accidentally shorted out a couple leads on my Rambo board the other day and sparks flew resulting in two stepper drivers getting fried. I ordered a ramps 1.4 board from Amazon (I'm located in the US) and it was honestly an easy setup!
Arduino Mega Ramps 1.4 hat Stepper drivers
I just plugged the hat into the Arduino, flashed the firmware from GitHub titled 'mpcnc_ramps_dual' (after I downloaded it I had to change the board in the platformio.ini from ramps to mega2560). Then I plugged in all the stepper drivers (dial to the left) and tuned them all to .7v (between a ground pin and the dial itself). Next, turned all the power off and then plugged in all the steppers and endstop switches. Next thing you know I was back in business and the board is replaceable for like 40 bucks instead of 140. I will say I overlooked the fact that my screen uses a different set of pins so you'd need something like this primarily for the adapter if you want to use the existing screen.
Feel free to ask any questions if you have any!