Alright following this post: The thread "Succulent going dark" in Cactus and Succulents forum and the fact that I dont think the plant will make it I decided to try a plan.
I have another succulent whose elongated due to lack of sun already, so the idea of to cut the tip of that one and the tip of the one that is going dark and replant.
First of my questions, are these good spots to cut them:



Two, I intend to put them in this pot, is that enough space for both (hand for scale):



And third: how much light and water should I give after the repot?

This is what I am using:



Thanks for everybody that read this far :D

More light first, then cut. The probability of success if you cut right now (given the way the plants look) is close to zero. You might try a leaf propagation instead. Otherwise dial up the light and wait until spring before taking action. Spring is generally a better time for this sort of thing anyway, with the stronger light and warmer temps it brings.

I cannot advise much on artificial light as I have no experience with that, but the distance from the light to the plant is very important (shorter is better, up to a point) and the light should generally be annoying and uncomfortable for humans to be around in order for the plants to reap the greatest benefit. See here for more:

The thread "Artificial light for cacti and other succulents" in Cactus and Succulents forum

The light is a good choice but it will have to be only about a foot from the plants and the plants will have to be directly underneath it. So one bulb, one plant. If the fixture doesn't have a reflector, make one to reflect the light normally lost up back down to the plants.

Thank you @Daisyl and @Baja_Costero !

Will do that