Plenty of 'bottle' dynos on the market to chose from, but they are easier to find in Europe than in the US. Call around. Union has bought up many of the old European manufactures like Soubitez, and still makes lots of inexpensive models. Busch & Muller (B&M) and Lightspin make higher end models. Peter White and Yellow jersey sell dyno units over the internet.
http://www.yellowjersey.org/litespin.html
http://www.peterwhitecycles.com/lightingsystems.htm