Both level shifters can be used. Even if the Sparkfun description is misleading, both are I2C level shifters. I2C means that each channel works in both directions, a low level on either side will result in a low level at the other side. Since your display has SPI interface, you don't need that bidirectional feature. I only mention it in case you cannot identify the input and output pins, mentioned in the Sparkfun description.
I don't recommend current limiting resistors, but a full voltage divider could safely bring a signal down. The buck converter may be required to power the display, but doesn't work as a level shifter.
I have no solution for the LED, couldn't find any description.