Here's a starter KIT system that has 140 watts and the controller can so 20 amps. You can add another panel later. The size should fit somewhere on your roof. 51x26.
https://www.solarblvd.com/product_info.php?cPath=1_272&products_id=2748Or you can do this one... 2 panels 45x26 which is better for shade and gives you 60 more watts.
https://www.solarblvd.com/product_info.php?cPath=1_272&products_id=2750The solar controller has adjustable temp compensation too.
As you decide what you want use a piece of cardboard and cut it to match your dimensions. Put it up on the roof and you can see where it fits.
There are lot's of choices out there... Need to shop around.
Jim