Joe is a good source, Judy over at pepperlover.com is incredible for variety and service, Junglerain( don't remember the website) has some interesting varieties as well. Check out the Vender's Vault.
All of the above are good, and JungleRain is good as well. Both JungleRain and THSC are relatively inexpensive. Avoid Amazon.com and eBay. Got seeds from both and got burned, no pun intended.
Probably best to read the Vendor Vault where it says:
[background=rgb(233, 216, 193)]Review seed and plant vendors. Post praises and/or concerns regarding vendors, their pricing, reliability, and more.[/background]