Since you will be getting two identical panels, it would be best to connect them in series and use an MPPT controller. This would cut your wire loss in half.
I have two panels but unfortunately they are not the same wattage so I have to connect them in parallel. I have two 50ft #10 extension cables so if needed I can plug both together and set my panels 100ft away from my coach. I'm in Florida right now and presently am hooked up with 100ft of cable and it is working okay.
When buying wire make sure it is 100% copper and not CCA(Copper Clad Aluminum).