Reading the instructions on those links, I was convinced that I should get either Carmona or Sageretia considering the wet, not warm or sunny climate of Ireland. I'm planning to have it at a North facing window with whatever amount of light it can grab from there, but for very few hours of daylight during winter. And the room temperature, especially at the window, would be probably between 15 C and maximum 24, 25 C.
On the other hand, the Ficus tree has a fancier trunk and looks more like a real tree, and that link suggests it's a good practice for beginners, as well as needing a lot of good sun (which I lack).
Now the instructions on the packaging is all the same for all four types of these trees as follows:
Which instructions should I trust and which one shall I get that would suit the most for my climate?
Update: I do have the lights on after the daylight is gone, but "light" I meant sun light (which is very rare in Ireland and at a North facing window) or just natural brightness. I do have home lamp light on till we go to sleep every night. I was confused because that website mentioned Ficus needs direct sun light.
Still looking for other answers as I'm not asking about making bonsais, but just picking one out of the four types. (: