I have just completed my first speer/banana hammock. I just followed Nomads Hammock pattern. The width is set by the 56" bolt, less an inch and a half which was used for the hem. The length was cut at about 10', and the ends are zip-tied with the sides pulled up 3".
I used camo ripstop to suit the cool weather and so that I can hang unobtrusively. Camo is all the rage here fashion-wise and so it is cheap and plentiful.
a bit heavy, though and weighs about the same as or a little more than my HH Hyperlight Asym - without the tarp or mosquito net! The thicker fabric is great, though.
The interesting thing about it is that I added a sewn-on stuff sack like the Nomads and realised that when I load it with some objects it can be thrown over the top to create a pod.
It's quite breathable and warmer. By putting my arms behind my head I can open up a bivi-sized hole.