two external monitors on macbook air 2018

I have a 2018 macbook air retina 13" running Big Sur, and I would like to use it with two external monitors plus the laptop display, with no mirroring (each one an independent display).

I have 3 Samsung monitors, two with DVI inputs and one with HDMI input. I did get this to work properly by using two cheapo dongle/hubs, one on each thunderbolt port. Unfortunately, one of the cheapo dongles stopped working after a few days, so it went back to Amazon.

So now I want to try getting this to work using just one of the thunderbolt ports. I think two HDMI ports off a single thunderbolt will always be a split signal, so they will always mirror each other, right? But maybe it will work if I get a dongle with an HDMI port and a DisplayPort, they can be independent? Or should it be two DisplayPorts?

I would appreciate any recommendations for brands/models of hubs that can do the 3 monitor setup plus has Gigabit ethernet and lots of USB-C ports, and ideally can also power the Air.

Or, if I am incorrect in any of my assumptions, is there a better way to do this?

Thanks!