Kits are fine but more costly normally. I choose 60 cell panels and MPPT controller which cost the same as equivalent 12V panels and PWM. MPPT performance is better and since most panels have bypass diodes the shade tolerance is also better.
Recommend you first install a battery monitor about $200 and use it to evaluate your usage not to mention it's value with solar. I used mine to evaluate every DC load. ie Turn off all charging then turn a light on/off and note the difference in battery amps, etc. Plus a decent monitor will also track your daily usage battery SOC etc.