2.5 or 2.8 dual coils are pretty tough to use on most equipment without using a vv/vw pv or mechanical mod. you would want to have some pretty decent power firing them, more then what most ego's can do. Most usually go with 1.5ohm dual coils.
as far as who makes the smoktech version im not sure, i never understood the difference by the picture. I simply always went with the same vendor i got the tank from