I get my dried from www.botanical.com - though it and the 2 mentioned by herbman are all excellent. I perfer fresh tinctures but if you are not an herbal manufacturer :) you usually wind up using dry. I have not found much difference at all in the tinctures to be honest.
You might be able to find some peppers at your local Whole Foods, etc. I have seen habaneros at my local grocery in the past few weeks...