Just get the cyclops and replace it only if the crystal is unscratched. Getting a crystal to fit will be a struggle and you would end up having to buy a plain one and fit a cyclops anyway.
As for the Movement, do you have a clone or a 21j in that watch? If it's a clone you need the same size ETA to replace it so it fits the movement ring. If you have a 21j, forget it, buy another 21j for it because you will need to get new hands, a movement ring and the dial seats differently as well. You will also need to replace the ETA date ring with the correct Rolex font and if you use a 21j doner watch the ring won't fit either so a new one is required.
AT THE OP (cazna): If you want to start learning movement repair I suggest you begin with a simple handwind in a large calibre such as a Panerai style of MVT. These can be bought from any of the above or from our own trusted dealer
jacksontse for very little money. Everything on these is a little bit bigger and they are a nice simple MVT to work on. I can send you the ETA tech sheet on them if you like, that will show you the exploded view so you know what goes where and it may have an animated strip down as well.
Col.
