As far as the Pro700 doing mapping and planter controls, yes you can feed the Pro700 gps from any brand source.
However if you want to use a NAV2/3 steering controller it will require a Trimble manufactured receiver. This would let you control steering through the Pro700 display.
If you choose any other steering system you will need a display made by that company to control it. Most also require a receiver to be from their company also to let you activate the steering system. Not always with steering wheel electric drives but always with hydraulic integrated autosteer.

But if you go with another brand for steering you can still feed gps to the Pro700 through either the serial ports or by the CAN buses. There are 2 serial ports, 1 as a 9pin built right into the Pro700 and the other in the main connector on the display wiring. There are also 2 CAN buses wired in the connector 1 for tractor side and 1 for implement side.