The iStick 50W is 4400mAh, that mod was certainly ahead of it's time, weird that there aren't more mods like that out there these days.
The Cube and the Rim are both good choices for a replacement despite their smaller capacity, both small and compact and comfortable. I'd lean towards the Rim...
We've just got our first batch of Yogi e-liquids in. This range was brought into existence by @Yiannaki some time ago and has now been taken over by @SEAN P. This is a truly amazing range of juices!
http://vapeguy.co.za/yogi-eliquids-vanilla-almond-milkshake-60ml...
The 40T is an awesome cell, I have 4 of them running in a HOG4 parallel/series mech, so far I've done 60mls of juice and will probably do another 30ml before they need charging.
I have great news for all the Smok Alien fans out there... It's back, better than ever! :D
The new Smok Morph 219 mod is the same size and shape as the original Alien 220, the 510 is now centered, the fire bar has moved to the other side of the mod and the battery door is now spring loaded...