I recommend watching some RDA videos on youtube before deciding. It took me a while to figure out what features I wanted and which ones I wanted to avoid, and videos from Grimm Green, Ruby Roo and Big Lou East Coast Review were a huge help in making the right choice. For instance, I knew I wanted adjustable airflow. So I got a Jam clone and discovered that the control ring is a pain in the neck. Then I watched a bunch of reviews and found that the CLT v1 has the kind I really wanted, which is adjustable from a knurled ring at the top, which allows you to adjust the AF on the fly without having to unscrew anything.
I also recommend checking out Angelcigs.com, as their clone prices are like Fasttech's, only they have their stock in the US so the shipping is fast and doesn't have to clear customs.
Best of luck to you!