And if you don’t want it to take a whole day to compress, I suggest using around 75% quality, faster (single pass), auto keyframes, and make sure you select AAC audio (128k is good), and fast start. If you don’t select fast start, the whole thing will have to download before they can play. And if you don’t choose single pass, it will take much much much longer to compress with negligible, if any, perceivable difference in quality. Also, turn off frame controls if they’re on and any deinterlacing. Scale to 854×480 which is essentially 16:9 SD and deinterlacing is not necessary.
You can export the exact same file with the above settings using FCP itself just using quicktime conversion. Should export in roughly real time. Export a small couple minute portion first to test obviously.