This step is independent of your OS choice, the downloaded image can be used on any OS.
However, the image is specific to the target hardware, as its name should reflect it.
Download Lakka for M8 ~ 400MB
Download Lakka for MXIII-1G ~ 400MB
Download Lakka for MXIII-PLUS ~ 400MB
Download Lakka for S82 ~ 400MB
Download Lakka for T8 ~ 400MB
Download links for development images:
Download Lakka for Amlogic GX