No ones going to sell that because its not to code things like Romex are meant for stationary installs behind walls, your basically making a 220V extension cord/power strip.
If you want one your going to have to make it yourself following his instructions and just use the proper outlets you want.
That said, how do you plan to control this element?
If your going to do this though, dont use Romex like this guy, Romex has no real protection from punctures or bending messing up the jacket..its meant to be in a wall or inside a conduit...dont want you building this thing and killing yourself in 6 months because the jacket chipped off somewhere and you didnt notice.