For the 530 non-phone version I used This one from ebay. It’s a different seller than I used, but this looks like the exact same part I bought a couple years ago. You need the screen and the control board version. This has HDMI, and I usually run it off of an old USB2 laptop docking station that has HDMI out. $41 with shipping.
For the G1000 I use this. 10.4" screen, 4:3 aspect ratio. $95. I will say that some of these 10.4" screens have had trouble with the HDMI control board, so be sure and test it right away when you get it. Some of them are finicky and don’t reconnect when you reboot your PC.
I’ve not found one I love for the 430. I bought a smaller screen for use with a Raspberry Pi, but to date I have still not finished building the 430. Need to do that before winter is out.