Stefan, of the plants you mention as possible alternatives only the Denmoza gets anywhere close to the size that that plant in the picture already is.
That plant is at least 20 cm wide so probably at least 60 cm tall, but probably more...
I will re-iterate that it looks like this plant when younger was grown in bright light - full sun conditions and now it looks like it is in a green house, or at least in conditions with more shade. When shade grown most cacti used to harsh full sun or very bright light conditions tend to make spines that are much thinner, smaller, and fewer in number.
I have no pictures of it, but I have a golden barrel cactus that I put in a pot to give to someone, but who ended up really liking another cactus so I gave her the other cactus instead. The GB got stashed in a pretty shady spot, for a bunch of months - during its growth period - and went from its typical fiercely spined look to something with very wimpy spines. I moved it into more sun and it started producing normal looking spines.
