How cool. Just reading your post gets me dreaming about that day in the hopefully-not-so-distant future when I move into my eco-palace and outfit it from top to bottom in gorgeous green-ery. I am on the west coast, so unfortunately can't tip you off to local spots, but I can give you a host of web-based suggestions.

First things first. Not to be a kill-joy, but we should stick to the golden rule of buying green: Reduce, reuse, reycle. The absolute eco-friendliest sectional would be one that doesn't require all new materials... i.e. one you buy second-hand. Have you checked craigslist.com in your area? It's not all dumpy old junk... The bay area craigslist is full of fabulous finds. My downstairs neighbor, for one, just sold her light tan suede super mod sectional that was close to brand new on craigslist for way cheaper than she bought it just cause she's your classic fickle interior designer type and decided it wasn't fitting her vibe. Sure the couches you find in vintage furniture shops or on the big C aren't necessarily going to include eco-friendly materials, but they've already off-gassed all they're going to in someone else's livingroom. Incidentially, here's the full low-down on furniture off-gassing from Healthy Child, Healthy World

If craigslist proves futile, here are some of my fave eco-friendly furniture purveyors:

Cisco Home - super style-y, cute colors and styles

http://www.ciscobrothers.com/ 

Bean Products - Organic hemp furniture in pretty colors...

http://www.beanproducts.com/ 

Greener Lifestyles: adorable. I know this one not a sectional, but I'm digging the cleo 

http://greenerlifestyles.com/ 

I know there have to be plenty of cool eco-furniture dealers right in your hood... here's what I found with a few choice google key words: 

http://www.vivavi.com

http://www.greenmodernkits.com/eco-furniture.htm

ooo, this one looks good:

http://www.bazaardelapaz.com/

Happy hunting!