Another shout out for the Viggo. You have to see one of these in the flesh to appreciate it. Ticks all your buttons too. 18650, Bottom Firing and (I think) locking ring. Slightly over budget but by the time it comes back in stock, you can have the extra £25 set aside.
The throw can be set to a ridiculously short level, if that is your thing, but the real winner is the threading. It is invisible when screwed together. It is next on my shopping list, unless the Tahiti by GP customs comes along first.
For something a little different, Shmovapes has the Pisces-T in stock. Bit smaller than most, but happy with 18650's. Not the hardest hitting mod, but a good performer overall.
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Mawsley I really love the look of the Akuma by GP Customs, but I think the price point is just a little too high at £150. If it was around the £120 mark it would have been pre ordered already. I know that £30 is not a huge amount of money, but it makes a psychological difference.
If you are planning on the clone route, then the Hcigar Nemesis from Vape Geek takes a lot of beating. Not much that I can say that hasn't already been said about this mod. You could get one and a genuine KFL+ for less than a tenner over your budget.
Some bits to think about.