Noobie looking for Tephrocactus Articulates 'Super Orange'

[Mujician]

Hi,
  This is my first post here, and I'm looking to learn. I'm also looking for a Tephrocactus Articulatus cv orange, or maybe super orange. There was one listed on eBay, but I haven't found any for sale since.

I would like to learn about cultivars, but I have no clue where to start. How did the first cultivar come about, and how are they developed? Is it possible for little old me to create something new? I'm mostly interested in Rebutia, Astrophytum, and Euphorbia. Thanks

[Carlo & Daniele]

Welcome on board! Have a look at the forum, there are many pics and info!