Oh, it's an e-pipe with a 510 tank (as far as I can tell).... (I do remember it, just)
Well, you can certainly put lower res' on that, but only so far as it takes 18350 batteries.
What rating are the original coils?
If it is a standard 510 fit, you might be able to use mini Nautilus or Protank type tanks.
Personally, I'd take a chance with an Eleaf GS tank and the 1.2ohm coils IF your 18350 battery is good enough. I have a bad feeling the battery that come with it won't be good enough though.
Try an AW or AWT 18350.