I don't think anyone can "guarantee" a particular mod will last for a year. The Jaq series do have an awesome warranty period, longer than most, and will also repair mods (sometimes even when out of the warranty period). The geekvape ages is definitely rugged.
If you want a dual battery mod, I am fond of Teslacigs, in particular the Steampunk nano 120, the copper model (in particular) seems to have issues with the battery door (particularly with a lighter mod on top, I have noticed that with my Siren V2, the problem went away... My theory is that the larger topper made better contact with the 510 pin, which resulted in a more secure connection. Prior to that I used a silicone sleeve. Some of the newer/other color Steampunks don't seem to have that issue. It's heavy, but built like a tank as it's all metal. I have dropped it, leaked through the 510 pin etc., and it just keeps on ticking. LOL. Not for everyone, but teslacigs generally is a good company who stands behind their products and they have all sorts of mods for all sorts of tastes.
I personally like the eleaf invoke a lot, it's one of the smaller, lighter 2 battery mods that doesn't sacrifice design quality. I am hard on mods, it has been dropped, I have "tested" LOL the reverse battery polarity and it's fine, it's a fantastic little mod for the price and I generally find eleaf products to be high quality and long lasting. Would make a great out and about mod, in my opinion. But, there are tons of options, and some very good options out there at the moment. Pick a reliable vendor and go from there.
I personally don't do well with KT products, for me they're a bit flimsy and while someone else might do fantastic with them, I am hard on my mods. It would also be unfair to blame KT for your issues, as you don't know if it's a fake or not. They are a good vendor to many people, I am just really, really hard on mods.
But, there are no guarantees for any individual mod, although there are makers who do tend to be more reliable than others.
Hope any of this helps and best of luck!
Anna