Hello.
From what I have seen, the Advken mods are fairly cheap to buy, if I remember correctly actually around the price of a good clone, so if you want the genuine product, there isn't much reason to not get it.
However, if you really want the mod in copper, and the clone is the only option, go for the clone.
I own a fair few mechanical mods, and the majority are clones and I enjoy them all. I mainly own clones due to price though- if an authentic mech was available cheaply I liked, I would go for the authentic.
Either mod will work, so it really depends if you want the genuine thing or are OK with a clone.