I think the thing you see posted most here is the need for instructions. There are lots of posts about people trying to get the device to work with their smoker. There needs to be some clear instruction on first steps to dialing in your PID. I know I am frustrated in trying to figure out why my device isn't keeping temp.
To push your product to the states, you may want to create a wholesale pricing option, so someone could figure out the profit margin for them to distribute. You will then need to stop selling directly.