2x2 double piston extender

Question

I am currently working on my modern house, which has a staircase looking like the picture below

It is about 10 Blocks wide, each step upwards is 2 blocks wide and only elevate the player by 0.5 block (slabs).

I am struggling to come up with a design to make part of my stairs shift down into my floor and change into a staircase which still uses slabs going downwards. So basically instead of a 10 wide staircase going upwards I want a two block wide section of it to "fall down" and reveal stairs going down.

Here is how i amagine it looking:

I do feel like I would need a 2x2 or even 2x3 set of double piston extenders to get my 2 blocks whide pathway downwards.

Is there any redstone enthusiast out there which can help me with a tileable extender for example which I can stack in this 2x3 grid?

Screenshots of the basic components would be enough, when get home in a few hours I hopefully have the time to show you what I need in pictures.

Answer 1

I found the answer to my prayers. a bit more complex than i imagined but i works none the less This little new friend of mine does the trick. 2 of them next to each other and another set of 2 on the other side and i had my 4 blocks going down. After that all i needed was a monostable running into another 2x2 single poston extender to make a long enough stairway.