Projections in a circular design

[Jamtastic3]

Hi BR,

For a show coming up in the venue I work in, there is heavy usage of visuals, the idea being that people watch the visuals from various projectors that surround them from a certain height.

Looking around for ideas, I found this nice set-up from a nightclub that is PERFECT for what I need:

 

http://www.youtube.com/watch?v=JWdNL62ixQ8

 

The only thing is that I'm not really sure how to go about this!

From the footage it looks like a barrel-type structure (2 rings and some verticals), made from flexible PVC tubing and pieces of material for the 4 projections (the 5th is on a back wall presumably as you can't see the 4th within the 'ring' of projections).

They've used circular truss to keep the shape of the ring effect but in my venue I don't have this, just four rigging points.

So how would I keep the top part of the tubing circular without sagging or distortion? I think the diameter of the ring would need to be around 4 metres.

 

Is PVC tubing the best thing to use or can I get metal circular tubing and verticals (something on the lines of a trampoline frame)?

What type of PVC tubing would I need that's rigid yet flexible?

Also, what type of projection material would I need?

 

Cheers folks!