Ok, searched digikey and couldn't find any sensor modules with better than 0.1c accuracy. I did find a nice +/- .05c thermistor which would come out to 0.09f accuracy provided it was read by an ADC with enough resolution. I still wonder, however, if component noise and the like might preclude that level of accuracy even if I did have a 16bit ADC? I figure there's a reason there aren't any sensor boards with better than 0.1c even on digikey :.
I tried searching on mouser and to my dismay found I wasn't able to filter by accuracy at all. Plus, I've heard mouser tends to charge a lot for shipping so it's best to order from them when you have a lot of components to get. newark also didn't bring up any promising results.
I may end up going with the .05c thermistor and a higher resolution adc, provided it's worth the extra effort/cost and is feasible.