This is the link for the Original Dark Silver Big Brother :
(136) Ren'Py - Big Brother: Another Story Rebuild [v0.01.00] [Aleksey90] | F95zone It was not completed because Patreon changed their policy regarding incest in games and he abandoned it.
There was a bunch of Fan Mods created for it and a Dev named Smirrniy put hem all together and added to the story himself with this one :
(136) Mod - Completed - Big Brother - Mod [v0.22.0.022] [the Smirniy] | F95zone. This game has gone the farthest in the story than any other and actually has a "Completed" tag for whatever that is worth to you.
Around the same time as Smirniy's game there was another fan created game that took Dark Silver's work and created a Ren'py Remake. He has now restarted that effort and it is here:
(136) Ren'Py - Big Brother: Ren'Py - Remake Story [v1.04 - Fix 4] [PornGodNoob] | F95zone
He has continued the Eric friend and fake friend story lines with his own story. For the most part the enemy path is the same as the original.
Dark Silver has also recreated 2 of his previous games into one it is called Glamour and can be found here
(136) Others - Glamour [v0.57] [Dark Silver] | F95zone it seems to be having issues with money right now it seems but does have a lot of content with the Max side of the game.
There is a game called Big Brother in Space that is based on the crew of a space ship that is rescued it is not the same characters as the original but has a similar plot but an entirely different setting. It is worth a look but is still in the early stages of the game. It is here:
(136) Ren'Py - Big Brother in Space [v0.5] [Lewd Fiction Games] | F95zone
Then of course there is Aleksey's game, which is the one I prefer. Aleksey has been adding more animation to his game which is lacking in both of the Dark Silver offerings and Smirniy's. This is not a complete list of the games, just the ones I have played and for the most part enjoyed to different degrees. There is still I think Max in the Big City and Little Sister as well but they are more of a sequel as opposed to a retelling.
I hope this helps with what you were looking for.
As for the second part of your question you do not need to load the Rebuild to play the 9.2 version of vice versa. The 9.2 does of course have much more content . the Rebuild is only one day and just a Demo to show how the rebuild will look with a new UI.