I would strongly suggest a mppt controller, as pwm controller waste a lot of energy.
The controller has to be matched with the solar panels. If you have more than one panel, you should connect the panels in series.
For the right size of the controller you have to mind the values of controller voltage and current.
1. Voltage:
The controller needs to have its capable solar voltage higher than the sum of all your solar panel voltages
2. Current:
The current can be calculated as the sum of the maximum power of all solar panels divided by 12.
If the calculated current is near to the maximum of the controller, take the next larger size to have a little reserve.
The controller should be placed near to the batteries with sufficient thick cables to have the lowest voltage drop. AWG size of cables you should find in the controller manual. Dont forget a fuse of proper size!
In my opinion a dedicated lcd display is not really needed, as the controller once adjusted does its work without the need of monitoring and the display needs place in the confined area at nav station.
For adjusting the controller a bluetooth connection and an app for the smartphone is pretty handy, like some of the victron ones have. Others needs an additional bluetooth dongle. If you charge lead batteries, the victron controllers offer a switch to select the right battery type, so you don't need the bluetooth at all.
Connections between controller and solar panels should be made with dedicated solar cabling due to its strenght against wear and tear.
If you have removeable panels, you should use solar connectors like MC4 ones, with provide electrical safety and water tightness. Remember that the solar panels generate high voltages, with can be potentially deadly!
I'm not so convinced about the victron mppt's, because my first one died in the second year of operation (luckily under warranty, and was replaced without further cost). Will see, if the second one has a longer life.
