A couple of Ideas
I use nursery-type shade cloth. It's won't keep out rain, but where I live if it's hot, it doesn't rain. If you want more shade, use a double layer. Sunbrella would work fine as well but it is more expensive and flaps more in the wind.I use two telescoping Forespar awning poles to hold everything up. One slides through a PVC pipe coupling lashed to the backstay. The other is held up on top of the boom by the main halyard plus a line to the mast for fore and aft tension. I have a rigid vang, so I don't have to worry about a split for a topping lift. I have light lines that clip to the ends of the poles and to my life lines forward and to the stern pulpit aft.I can also rig this from my dodger back to the backstay so I can sail with the sunshade up. Since it's mesh, you can see through it to trim your main and see your windvane.Aside from the awning poles, the cost of all this is negligible.