any of the AGA's or DID clones are a great way to start and see if it is for you. be warned though the first time or 2 can be frustrating, but when you finaly get it the huge choking plumes of vapor will make you go "oh yea"
Agreed, they'll frustrate the devil out of you when you first start tinkering with them, but they are worth the effort. When you finally get a coil and mesh set-up that fires right the first time, you may want to sit down, lol
The china ones already listed make for a great cheap intro to the RBA/Genesis Attys. If you try them, and fall in love, it's worth the cost for the originals. The DiD clones are good, but pale compared to the quality you get from the ACTUAL DiD. I have a few I use as test beds for playing around with coil set-ups so I dont have to disturb my Line or DiD set-ups, same with the AGA's and the Nix clone.
Though I will warn against the SmokTech rebuildable, had 2 of those clunkers fall apart just removing the tanks on them. Quality is sub-par on those, even for China.