The array.
Panels are the only part of the system that is not in a cupboard, and the only part sized against your roof rather than against your bill. They turn daylight into DC and hand it to the inverter.
The hardware behind the system.
Ten brands go onto a Sun Savings roof or wall, across the three layers every install has. Which ones you end up with depends on the sizing, the stock and the warranty that suits the job.
Every install is three layers.
An array, an inverter and, on all but the grid-tied systems, storage. Each of these brands supplies one of the three, so the useful question is not which brand is best, it is which layer it is for.
The inverter.
The box between the roof and your distribution board. It converts the array's DC into the AC the property runs on, and in a hybrid it also decides, moment to moment, whether the load runs off the sun, off the battery or off the grid.
The storage.
The surplus has to go somewhere. Lithium storage holds what the array makes and the property does not use, which is what there is to run on after dark and what carries the specified circuits when the grid drops.
Storage on a real wall, on a real job. The brand on the case is decided when the system is sized, which is why the specification comes back with your quote and not before it.
Brand is decided by the sizing.
Not the other way round. Send a recent bill and we come back with the specification, the brands in it, and what it costs a month.