Where to find dry red spur chili (phrik chee fah haeng, พริกชี้ฟ้าแห้ง) or substitutes?

[YevZ]

Hi, when I was in Bangkok I went to a cooking class and got a recipe book. Most of the dishes need dry red spur chili, or as they call it in Thai phrik chee fah haeng (พริกชี้ฟ้าแห้ง). I live in the San Francisco Bay Area, California, USA and can't seem to find it anywhere. I also can't seem to find it online. I found one UK website, but they don't deliver to US. Any idea where I can get it online, or what other peppers can be used as a substitute? I know there are many peppers that look similar, so I don't want to buy the wrong one and have it turn out bad. 

[Oxx]

Google is your friend.

 

http://www.spicesinc.com/p-3876-thai-chiles.aspx