Most of the Pentel S15/19 don’t have anything on the body. The clip does have some thing impressed/engraved on them. Early S5/7/9s, ML5, P505s also. So actually many Pentel pencils are like that. There are too many to list.
I think your first question mostly doesn’t have much to do with the pencil - it’s the lead that counts. In general softer and smaller diameter (smaller contact area) lead will be less noisy. It also shouldn’t be too sharp - sharp edges make more noise. The pencil does matter a little in that it should be able to handle smaller softer lead.
I would try the Orenz Nero in 0.2 or 0.3 with HB/2B leads. For lead brands, I would recommend the Pilot Neox. I find them to be the smoothest in comparison to other major brands.
I don’t think I can answer about noise, since I don’t mind it at all. I do prefer “muted” noises to “metallic” noises if that makes sense. Parts rattling around are quite annoying. I always liked how the Pentel Kerry sounds with a soft lead.
You can modify pencils to make them less noisy. If the clicker is rattling around, you can wrap one or two layers of cello tape to improve the fit. If I had to take a wild guess, I’d say that thinner materials would lead to higher pitch noises, while thicker ones lead to lower pitch ones. If you write on a notebook instead of a single sheet of paper, the noise should be reduced considerably since most comes from the lead hitting a hard surface.
About text on the pens, I’m not sure if you want to modify them but you can easily erase printed text on any plastic. Acetone/nail polish will wipe any print almost instantly. Beware, some plastics get damaged by doing this. A less intrusive method, but more time consuming, is rubbing it off with an eraser. It takes more time and if the print is hard to remove it may not come off at all, but that’s another option.