The Snugpak poncho seems to fit your requirements but doesn't have the grommets etc for use as an impovised basha shelter.

http://www.outdoorgb.com/p/snugpak_ponch...tedBundle=95965

I have this Goretex Poncho;

http://www.militarykit.com/products/jackets/british_army_dpm_mvp_poncho.htm

It is great for field use, has the grommets and studs etc so can be used as an improvised basha shelter and is made from what looks like the older 3 layer Taslan Goretex (so is very durable, but slighlty heavier at around 900gms, so doesn't blow around too much).