fitting aftermarket remote central on a mk4 will be an absolute nightmare in fact nigh on impossible due to the way the door pin protrudes through the metal inner skin
in this instance i would suggest buying a genuine central locking kit and electric windows (you will have to fit the windows aswell as the central locking is all tied into the windows)
the car may have the wiring already in place in the footwells for the locking etc already but as i have never worked on one without locking already i could not say for certain
if it doesn't then you will need the complete loom including the ccm module and even then if you have the remote keyfob for the new locking it will probably need recoding to the car
personally i would get the original locking etc and add a decent good quality alarm (not the one you linked to that will be rubbish)
