No clue what's good in the solars but here is a thought. More inlet screens (the 2x4x24's) will produce a massive amount of ventilation without any additional mechanical supplement. In the summer heat, I open the access panel in the garage and a huge current of air rushes through. A gable vent is also a good idea.
I have that exact setup (the two of them pictured) pictured on the solarfanatics website. It's quite good, they move a good bit of air, and they've held up to 3 direct hit hurricanes.
This model is available from various sources, so make sure to shop around for a good price.
You need draw from the right locations to move heat out. If you use an attic fan, you should seal your gable vents and have no ridge vents only soffit vents. This will create draw from the bottom moving heat out. Your attic fan should be near the peak. If you put an attic fan in without blocking the gable, and have a ridge vent, the air will pull from the gable or the ridge vent but the doctor vent. You will not be moving the heat away from the inside ceiling of the living space of the house.
Also you need velocity. Drawing from the larger gable vents you are not creating velocity. It's best to draw from a smaller area to create velocity, which the soffit vents are.
Our two powered attic vents needed replacing so I looked into the solar powered ones. For us the cost was prohibitive. We ended up with two standard electric powered replacements installed for less than the price of one solar powered model in a box. No doubt the solar would prove less expensive in use over time but we're in (or near) our 70's so standard power made more sense.
When I researched this years ago, I learned that the electrical fans move a ton more air than solar for less money. I just don’t know that any of the solar powered one would make a noticeable difference. That’s why I chose not to get a solar fan
Had 2 Remington 20 watt solar fans about $200.00 each from home depot. They keep our attic a good 15 degrees cooler that out door air and worked well for 3 years then we had a bad driving hailstorm in 2016 and it shattered the solar panels. Did not feel like spending $400 again so elected to go with 2 cheaper passive spinning turbine vents instead and they seem to work well also. Not sure how often you get hail storms in LA but if you do not get hail or hail is very rare a solar fan would probably be the best option.
My house was built with ridge vents. They are definitely effective, but by adding an electric (not solar) fan to the mix I measure a 10 degree temperature drop in the attic area that is directly above the ceiling.
I have two mounted near the roof peak. I live in South Florida, so it's sunny and hot. They do not move anywhere near as much air as a big 120V powered fan would. However, I've also found that I don't need that much air moved. As these things are sufficiently capable of moving the heat out.
My home is 2500 square feet, plus a 3 car garage with a large storage attic over the garage, and a good sized patio. Total roof area is about 3500 square feet.
My house has eves that are well vented and just the 2 fans. The airflow is clearly robust, and standing in the attic staircase, one can feel the upward airflow.
The attic temp is maintained at roughly the outdoor temp. It's no problem what so ever, to go in the attic and work.
My previous home had ridge vents. The attic was regularly 140 degrees.
Ah ha! I've found the actual brand (natural light) and they are available here: https://www.amazon.com/Solar-Attic-24-watt-25-year-warranty/dp/B001OULVQM