The above is the fully correct way in doing it however when it comes to the MOT (and this is still a grey area) you don't need to have the auto levelling and washers. The MOT documentation states that if the car has them fitted then they need to work, if they are not fitted then they won't fail the MOT.
One thing that causes some issues is the way the light beam shines due to dirt on the headlights (hence the washers) but as long as they are clean before the MOT you will have no issues.
JonTDi did a Bi-Xenon retrofit
guide in the Mk2 FAQ section which lists the parts you require. I'm actually going to be doing a retrofit of Bi-Xenon FXR projectors fitted with HIDs and a halo (amongst other bits!) and I'm currently awaiting these parts to arrive.
Good luck if you decide to do it!