http://makersrow.com - this is probably your best bet.

I wouldn't use a website though.

I'd talk to entrepreneurs and creators of high tech textiles in the USA. Look specifically at http://titintech.com and Klymit jacket. Reach out to those founders and learn as much as possible. Both of them are really nice guys and might be better equipped to share horror stories as well.

Also be sure to look at http://reddit.com/r/textiles

Textile trade shows are a great way to find textile/fabric suppliers. Trade shows such as Texworld and the IFAI Expo are two of the many trade shows you can attend in the US. If you have the budget to travel overseas, Intertextile Shanghai is one of the larges trade show that focus on suppliers from Asia.

Depending on if you're looking for custom textile manufacturing or just looking to find a textile line to buy and use will impact your approach to finding the solution your looking for. In either case, I would suggest you visit your local re-upholstery shops. Visiting 2-3 of these shops and asking them who they buy upholstery from will quickly help you understand who the manufacturers, distributors, and brands are.