I would like to upgrade from SS4 to SS6. Our current SS4 which was setup by our administrator who no longer works here is based on the US dataset. As we work in the metric system here in Australia I was wondering should I install the NM dataset this time. However the company I work for is American and we have been given imperial linestyles to use so my other option is to run with the US dataset and change the uom to metric.
I would recommend you look for the USM dataset (U.S. Metric) . It is based off the imperial version of the US dataset. I believe this is closer to what you are looking for and offers more of a soft metric conversion to work with the U.S.