I need advice on the best method for attaching netting to the ceiling/frame of our deck.
We are building a cat enclosure by netting off part of the deck. In the photo below, the part that will be netted off is from the timber post on the right of the herb garden to the right hand wall, and from that same post to the left frame of the window to the right of the fridge.

So the netted section will be kind of triangular.
We have already bought netting and the company we bought it from recommended using wire rope to clip the netting to. The wire rope is held in place with eyelets that screw into the various surfaces. The eyelets can easily be screwed onto the window frame, walls and post as these are all timber. But I’m not sure how to attach it to the top surfaces.
The ceiling of the deck is plasterboard and only about 5mm thick. I don’t know if it will be sturdy enough to drill eyelets into or that this will support the weight of the netting (or any cats that might climb up it). For the section on the front of the deck, we can either attach the eyelets to the plasterboard ceiling or to the hollow metal/Colorbond frame that runs under the gutter. I have the same concerns about sturdiness, don’t know what fasteners to use (the screw eyelets are not suitable) and don’t really want to drill into that frame anyway.
So I’m thinking about getting treated pine framing timber and running it across the ceiling from the post to each wall and using heavy duty brackets to hold the timber up. This would create a frame to attach the netting to using the eyelets and wire rope. We have already done this for the base of the enclosure by using treated pine framing timber to connect the post to each wall - the netting will be attached to this frame rather than the deck.
However, I don’t know if a bracket on each end of the framing timber would be string enough to support the weight of the timber and the netting. One of the timber pieces would need to be 3.6 metres long and the other 2.5 metres.
What method is best to attach the netting or are there any other options?