although ive not watched this video
i dont see how you can get a pre engineered FSD better than Grade 5
i would hang fire on that iiwy (unless you want to get it for fun of course) to answer your question however the one in the video is better because it has double engineering, something we cant do normally, that is a special version of the FSD.
with the new update that is currently uploading to servers today (7th May) a new type of FSD is coming, one which gives you a huge speed boost in supercruise - a version of that is already in game now but an improved one is coming - but also gives you a range boost in hyperspace as well.
servers are down right now. as of this afternoon it will be in game via the paid (with cash) python 2 - which will be available to buy in game from the 7th August, tho not with the engineered parts.
whether the new FSD will also be locked behind the cash store for 3 months, i am not sure (and i am not gonna go into the P2W arguments there, i have done my bit of that on the elite forums). it maybe you will be able to get the FSD in game as well from this afternoon in which case "yay" but if not, i think the preengineered ship with it on is around £15 worth of ARX. (I will be waiting)