i would agree with 'wannabeartist' - that using cloth would get you the most accurate result. you wouldn't need to do any inflation though - so that would make the process one step easier. with a tent - where all surfaces are in tension - you can only get either all concave or all convex surfaces (depending on whether you are looking at it from the inside or the outside). inflation, in this specific case, would give you both concave and convex - which produce a form that just wouldn't look right.
with cloth, you simply have to "fix" the edge conditions and the points which define the peaks. then you just run the simulation - and let gravity do its thing. even though in the cloth simulation, you are "hanging" the cloth. for representing the surface that you are trying to make - it is the same as pulling the whole thing into tension like a tent.
attached is a rendering of a bridge design that we did where the surface was "form-found" using cloth simulation in MAX. the rendering is a bit hard to read. the whole project was done in 20 minutes for an Autodesk "Design Slam".
