Hey, I am going through the same parts on my 91 as well. I personally wouldn't change springs unless:
1) they are damaged, broken, or noticeably sagged.
2) you want to lower it.
3) you want a stiffer ride, and don't mind that that means lowering the car.
I'm working on coilovers (cheap) so that I can stiffen without dropping the car much.
The upper mounts are not included with the struts, but they are available on thier own, ask for the mounts/bushings when you get the shocks. Someone else may correct me, but I think the Passat (91-93?) strut bushings are better and drop right in. If you are replacing with stock level components, you MAY want to ask about availability of (Monroe, IIRC) 'Quickstruts'. They are not always available (depends on the car), but they are springs premounted on struts, so you get both components and do'nt need a spring compressor. Don't forget that you will need an alignment after you do the struts, as the camber setting is largely in the strut/spindle attachment.
Good luck.