AxlPivot

Good day my advise is to do 2 in series X3 strings reason being 3 in series its too closer to your MPPT Max I dont think its safe and total watts will be 1980W - 20% depends on your wiring you will probably get around 1500W on 6 panels, secondly on the load depends how big is your load but ones everything is connected you should be able to see if 6 panels are good for your load or not and you can add another string.
I forgot your last question on the best results in terms of 2 or 3 in series that's not really matters because your total watts will be the same weather 2/3 in series on what changes is VOC and AMP'S

2S would be best.
Voc of 47 x 3 = 141 V, and that's at 25°C. That's way past the specification, and even well past the 130 V where power will be reduced (derating begins). At 0°C, it's usually about 7% more voltage, that's over 150 V, which is over the never-exceed voltage of 145 V.
The now uncommon 60 cell panels are good to connect 3S, and in fact 2S is probably too low a voltage in some conditions.
My rule of thumb is don't connect any panels 3S if they are over 45 V Voc (at 25°C, as they are usually quoted). This is of course for the solar charge controllers with a 145 V maximum; some have 115 V max, and other models have 450 V max or more.