I like the little soft tip cartomizers. They have the same heater as the 808D-1 cartos.
Hold about as much juice as a 510 cart (maybe).
I took some photos of one taken apart, maybe on the easy to refill a cartomizer thread, or somewhere. One photo of one on my paperclip MOD in one of my profile albums
http://www.vapeatron.com/members/roc...lipmod-105.jpg
Lecig is where I got mine.