... if it were me, before I spent any money I would document exactly what hardware and software interface I plan on using (DSI/MIPI, RGB, etc) and sort out at least a handwavy plan on how to make all that work first. If you are using DSI, does your controller support enough lanes for the display you want to use? Does the datasheet have all the configuration commands and sequences you need? If you need to make hardware, sort out what the clock speed/layout guidelines/connectorization need to be on the boards. If you need to power the display, sort out what power supply requirements are (multiple voltage rails, current requirements, power up sequences, etc).