I couldn't find any tips among the in-game tutorials about these signature weapons. So what is it ? Is it some kind of overpowered version of other existing weapons ? I'm asking because I couldn't find any equivalent in the other shop's weapons. For instance, the Shredder:
The Shredder is unlocked when you have found 10 Memory Cards. It is a customized Vektor SMG with a suppressor, extended magazine and optical sights.
Vektor SMG ? It that supposed to be a regular weapon I'm not aware of ? Maybe I haven't found it yet, but then is it normal that this signature weapon gets unlocked ?
Also, it looks like they come with attachments and custom paint corresponding to your play style. For instance, I'm mostly playing stealthy and I like to paint my guns in red: the 3 signature weapons that popped in the store so far are red and equiped with sound suppressors. Is it just a coincidence ?