Here's my design for a lie down workstation I've used for weeks at a time.

1. open an ordinary laptop screen to 180 degrees.

2. Place the laptop face down on a desk with the laptop's screen hanging over the side of the desk.

3. Put a big heavy object on top of the laptop (I used a hug e book).

4. Plug in your peripherals and put them under your desk

5. lie down underneath your desk so you can see the monitor

6. rotate the display settings as necessary.

Advantages:

* lying on the floor is great for your back

Disadvantages:

* Make sure book is huge enough, otherwise laptop comes crashing down on your head.

* Monitor space is limited to a single laptop screen.

You may have fancier requirements that require a trip to the hardware store. OTOH, you might not. the real trick here is I only need one small monitor to do my job.