That leads to the question... It's a commercial radio, is this for a commercial customer? Because the parameters that are acceptable to an amateur application are not necessarily acceptable to a commercial user.
For starters, use the manufacturer specified receiver sensitivity. It's going to be closer to .15 microvolt, not 1 microvolt. But if it's a commercial application, you need to factor in some real world losses that a radio is going to find between it, and the transmitter it's trying to listen to.
It's a complicated process, and Radio Mobile is NOT a user friendly program to try to figure that stuff out with. I've compared it with very expensive commercial software and found that, while it has the tools to run some pretty accurate coverage plots, it's no where close to intuitive, and unless you get all the details right, the plots can come out pretty meaningless. Especially if you're looking for specific received signal levels.
It does ok in defining the shape of the coverage area, but it can do a lousy job predicting actual signal levels. That takes repeated plots, field measurements, tweaking to the parameters in the software, more plots, more field measurements... and so on.