Have you looked at the
istick? It is a very small box
mod that can go up to 20 watts with a 1.0 ohm coil (according to PBusardo's video.
It does has a few problems regarding how its chip works (it is built on using mean vs using RMMS) so it can't reach 20 watts on all
coils and does run "HOT". It is not capable of down regulating power (it is widely inaccurate, especially at lower voltages). As long as you're aware of it and don't need a battery that can output voltages between 3v and 4.2 volts, you may like it. I know I do (and I have several MVP's as well). Here in the US you can pick one up for about $35