What is the widest range 9 speed cassette? My commuter rig is an old trek mountain bike that I've converted to fixed gear with an ENO hub/crankset.  I am thinking about going geared for the winter.  I have a rear wheel that I built last year and never used (found the eccentric wheel on craigslist around the same time), an SLX rear derailleur and an LX shifter.  Looking for a wide range cassette so I can take the bike offroad a bit more often, but I'm hoping to keep my 42t chainring on.  I'm willing to take the risk that the ENO ring can work with a 9 speed chain.  

The best I've found is a shimano CS-HG61 (12-36) which I think would be more than enough, but if there's anything bigger available I'd like to know.  Not interested in mods/adapters.
If you are looking to go faster on the flats you can find multiple cassette models with a range of 11-34. If you are looking for more "granny" on the hills, 12-36 is the best you are going to find out of the box without swapping out the low ring. (Sheldon Brown)

That said, on most 9-speed cassettes I have seen, the smallest ring or two are not riveted to the body, so you could easily swap the 12 out for an 11 to get that much more range.