First thing you need to do is do an energy audit to see how many watts you need and then figure out what area you have for your roof.
For every 100W, with a PWM controller, you can potentially get around 5A peak but that is if you tilt panels. If they are flat mounted, figure 20 to 30% less. You can look up charts to see what the equivalent sunlight hours you get for your area but you can also use 5 to 6 equivalent hours in the summer as a rule of thumb. Therefore, a 100W flat mounted panel can replace around 24AH per day with 6 equivalent sun hours.
I suggest this place for US made solar panels that are less then $1/W if larger panels will fit. Always better to use 1 200W panel than 2 100W panels.
Stay away from kits.