Whoa... this could be a challenge.
Are you absolutely sure about an e-pipe?
What sort of tanks have you been told leak? Not everything leaks all the time... of course not... The word "Vivi Nova" fills me with dread in all honesty.
...and JacVapour too. (I had the V1 kit from them... 3 times the price of what I paid for one from Myepack...)
If it's a pipe you want, you need one with a 510 thread, then you can choose anything almost. A pipe isn't usually Varible power... Smok (smoktech) make one, but it's a disaster from what I've heard.