GPS for RTV Spray Unit


I am the agronomist for a 1000ac. hazelnut farm. We use an Kubota RTV unit with a 100 gallon tank and 3 (4ft) booms in the front. What’d I’d like to be able to do is track spraying across the farm. I do not need autosteer, but would like to simply track and log the whereabouts of spray activity. I could buy the Teejet Matrix 430 to do what I need, but I’d rather build my own using AgOpenGPS. If anyone could please help me figure out what parts I need, and software, as this is my first time building anything of the sorts; I would really appreciate it!