The only fixed, multiple gear arrangement you'll find is an internal hub, like the Sturmey S3X: http://www.universalcycles.com/shopp...&category=2713
As others said, running a fixed gear with a derailleur will likely snap your rear derailleur off. I had a rear cassette seize up one day, and I was barely able to limp to the next sag stop (on a supported tour).