There's a few steel breech upgrades. Crosman produces the canonical one, which is pretty nice. Yes, I think most silencers will need a longer barrel as there's no space to attach a silencer mount on the stock barrel -- it's too short. You probably also need to acquire a nose-piece for the new barrel, i.e. a threaded bit that allows for a silencer mount. I think there are 3d printable ones, as well as milled aluminum ones available.
3d printed parts can last a good long while, if you use the right material for the job. Printing with plastics, you do have to take a little more care in regard to the exact application. And of course, the 3d printable part needs to be designed appropriately. Often times that will mean the part might be bigger than a corresponding steel or aluminum part.
It's probably best to think of the 13xx platform as something you can buy-into with relatively little money. But then you can slowly upgrade it and personalize it to your taste. If you do a lot of modifications right away, it might make more sense to purchase a gun that is more sorted-out to your tastes, from the beginning.
