imho rfid readers add another level of complexity, as does indicator heads that record data.  I am experimenting with rfid and will get there eventually but right now don't have the confidence to rely on it only.

Starting out on a short time table I would go with keep it simple. A non recording EZweigh indicator with a notebook and pen in your shirt pocket is simple and reliable.  The scale weights are the most important info.  I then take the handwritten list and in the evening make a simple 2 column excel csv spreadsheet of eartag number and weight on my desktop computer and let Cattlemax read the spreadsheet and make the entries.