You will need to call Crosman at 1-800-724-7486, ask for Parts and tell them the Part Number you want.
It might be helpful for you to do a "Search" for a particular topic here on the forum or check out the CFTech section, here is the link http://www.network54.com/Realm/CFTech/CFTech.htm. This is always a good place to start looking at possible modifications. There are also many other links to sites that you can check out here http://www.network54.com/Index/12861. You will need to do a little homework, read some and then decide what types of modifications that "you" want to make. After you have done these types of things, then it is time to ask the questions.
Not trying to be harsh here Roberto, but you might be happy as a clam with a $60 gun or you might want to put over $1000 into it, but you have to figure out what you would like to do with it first.
Hope that helps give you a place to try and start. You will also need to keep in mind the fact that you are in Canada and you are limited by law the power that any gun you have can produce, unless you have a permit or license or whatever is required. Keep it legal!
"No free man shall ever be debarred the use of arms. The strongest reason for people to retain their right to keep and bear arms is as a last resort to protect themselves against tyranny in government." - Thomas Jefferson
Current cache - CR 1377 Pistol, CR 1377 Carbine, CR CS2250, CR CS2240, CR 2300SLE, Gamo Silver Shadow Supreme, RWS 460 Magnum