17 oz is heavy for a poncho, even a full length one. My Golite poncho is about 10 oz or so, and one I bought from Campmor a couple years ago isn't as long but is 2 - 3 oz lighter than that.

I'm not positive all of these are still sold, but if you really want to survey the field, search for specs and prices (and reviews) on some of these too:
- Integral Designs Silponcho
- Sierra Designs Hurricane poncho
- Equinox Terrapin Poncho
- Bozeman Mountain Works SpinPoncho
- Poncho Villa from Antigravity Gear
- Mountain Laurel Designs MLD Pro Poncho
- Stephenson’s Warmlite Poncho
- make your own, for example patterns for Poncho and Parcho at Questoutfitters.com