I'm not stuck on Giandel but I do look for stuff that is reliable and wanted some type of warranty. I have saved the Giandel 24v 4000w inverter in my bookmarks. I have also been looking at the SOK 24V battery. Also looked into Victron 250V / 70A and rich solar with their solar panels.
One thing that is on my mind is would I be needing a bigger inverter or a 2nd inverter for this system later on.
If you are thinking of going bigger, you may want to look at inverter/chargers that are stackable. Magnum Energy, Schneider Electric and Victron Energy are a few tier 1 manufactures that have stackable inverter/chargers and there are others. Inverter/chargers allow the battery to be charged from the grid or generator. They cost more, but depending on the system can be worth it.
The nice feature of inverter/charges at tier 1 manufactures is programmability. Inverter/chargers can be programmed to switch to the grid when the battery gets low and charge the battery among other features.
Another item to consider is a Low Frequency (LF) type inverter that can typically handle a surge load for 30 seconds or more. High Frequency (HF) inverters typically handle a surge for milliseconds. The LF inverter can usually handle starting surges, such as you air conditioner, better than a HF inverter. LF inverters usually weigh significantly more than HF Inverter because of the large transformer.
The SOK 24V battery has good reviews. I once considered their batteries for my system, but opted to build from cells.
The Victron Energy 250V / 70A is a good quality solar charge controller.
Rich Solar makes good solar panels. I have 3 of their panels and they work well. I did need to touch up the caulking on the back of the panels. Also, one arrived with broken glass and had to be returned, but this is common with solar panel shipments. I would buy Rich Solar panels again.
Check the return policy when having solar panels shipped.
For my next purchase of solar panels, I am going to look for sales at Home Depot, Lowes and local outlets and hopefully good panels can be found there. That way the solar panels can be ordered into the store and I can inspect the panels before accepting them. I have had 3 solar panel shipments and all shipments had some damage. It can be difficult to return damaged panels, because larger panels are delivered by shipping companies and I found some difficult to deal with for returns.
If your system is a 24 volt system it is recommended to buy 24 volt panels. 12 volt panels can be used in a 24 volt system, but the panels need to be series connected to get the voltage above 24 volt. My solar system does have three Rich Solar 12 volt panels, but they are connect in series to get the voltage to about 50 volts. The other panels are 24 Volt so a single panel can be configure parallel if needed.