If money is no object, Z-Packs has a diamond hammock tarp
. 4.3 oz / $175. I know people who are satisfied with coverage of this tarp with their Blackbird. But they do use it as fair weather tarp. Plus you only need 2 stakes.
Ridge Line: 11 feet long (3.35 meters)
Width: 8.5 feet wide (2.6 meters)
Short side: 66" (1.68 meters)
Long side: 103" (2.6 meters)
Weight: 4.3 ounces (122 grams). Stuff sack included.