Panel warranty’s all are pretty consistent in 10 year manufacture and 25 year production warranties.
Micro invertors come with a 25 year warranty and most string invertors are 10 to 12 years. Will of course determine once final equipment is selected.
Maintenance is practically nonexistent as only potential need is cleaning the modules occasionally and frankly with the rain and snow they tend to stay quite clean naturally. If you ground mount your modules that may require some cleaning annually based on your location.