Good Grief, he asked some pretty simple questions!
The 901 is still around, I still use the 901 atomizer, but on a battery '
mod' like what is found at puresmoker and many other places.
The workhorse ecig is the 510, can be found just about anywhere.
A few people swear by the 2 piece models, k808 or something like that.
Gave you a few things to check out I hope.
Welcome back and Best of Luck!!