Questions before buying: Wi-Fi AP available? Power saving modes?

I have recently completed a project on a Raspberry Pi 4 that I think would work better on the Rock Pi 4 because of the M.2 slot.

I need to know a few things before remaking the project on the Rock Pi 4:

How do I enable Wi-Fi AP mode? I could not find documentation on this topic, I am unsure if the Wi-Fi chipset supports AP mode and is supported by hostapd, isc-dhcp-server, and iptables

What are the available power saving states that can be entered while running embedded linux? The Raspberry Pi 4 does not have any except for CPU halt that doesn’t retain RAM. Is there a power state that halts CPU but retains RAM? How about CPU periodic-wakeup, retains RAM, power saves on PCIe, and also keeps Wi-Fi clients connected?

The project I am porting over is https://eleccelerator.com/bucket-wireless-photo-backup-culling/