I would really strongly suggest staying away from the Paradyme.
The AgLeader GPS6500 receiver(Novatel core) and SteerCommand is the way to go. Theres nothing wrong with the older ECU4 steering controller used with a Paradyme but the Paradyme itself will disappoint when compared to the Novatel based receiver product line.
Paradyme is very slow to just get a WAAS fix. If used on a self propelled sprayer it will loose WAAS fix at about 25mph and takes several minutes to reinitialize when you stop at the field. The GPS6500 takes just seconds to get a WAAS fix and betwwen 30 seconds to 2 minutes to get an RTK fix. Glonass is also standard on the GPS6500.