Are you addressing the roof solar jack with MC4 plugs, or the "solar on the side" with the SAE connector?
I have 640 watts of solar on my roof and it's very adequate for my needs. My converter 120VAC power breaker is always off, the solar keeps batteries charged and runs all of my 12v loads. I have a 2400 watt inverter that can run everything except A/C, which is a huge power hog. A decent battery bank is almost a requirement to get the most benefit.
Sizing solar equipment depends on your planned use, start with figuring what you need to run and how much power is needed to run it.