Taking Sides: Tetsuo The Iron Man vs Tetsuo II: Bodyhammer

Aronofsky's 'Pi' gets cited a lot as a Tsukamoto-borrowing.
The two short films he did before Tetsuo are kind of fun to see & are basically even rougher drafts of the same ideas.

Tsukamoto started making movies at the age of 14, when his father gave him a Super 8 camera. He made a number of films, ranging from 10-minute shorts to 2-hour features, until his first year at college when he temporarily lost interest in making movies. Tsukamoto then started up a theatre group, which soon included Kei Fujiwara, Nobu Kanaoka, and Tomorowo Taguchi, all of whom would continue to work with Tsukamoto up through the filming of Tetsuo: The Iron Man.
One of their theatre productions at this time was Denchu Kozo no boken. At the end of the production, Tsukamoto didn't want to waste all the effort they had put into building the set, so he decided to shoot a film version.
Tsukamoto's early films, Futsu saizu no kaijin (A Phantom of Regular Size) and Denchu Kozo no boken (The Adventures Of Electric Rod Boy) made in 1986/87, were short subject science fiction films shot on colour 8 mm film. In both films he made aggressive use of jarring editing, stop-motion animation, bizarre sound effects, and grotesque or outlandish subject matter. Denchu Kozo concerned itself with an unhappy young boy with an electricity pylon growing out of his back, who is transported into the future and must do battle with cyborg vampires trying to destroy sunlight

I really want to see this.

Is he responsible for that 10,000 volt movie with the guitar as electro-weapon battle?

That one was directed by Sogo Ishii.

Is the first one "available," as Alfred would say?

watched Tetsuo: The Iron Man, my first Tsukamoto film. thought it was very strange and hard to relate to