I am considering using a Raspberry PI 4 as my next router.
- What antennas should I buy (I need both 2.5 and 5 GHz networks) ???
It should be noted that I live i a very very populated area. Does it make sense to buy a mega Alfa Antenna ( Alfa AWUS036ACH) to burst full power or does it not matter ?
None, outsource the wireless to an (OpenWrt supported) AP, there are ni good USB WLAN cards for these purposes.
for the price asked, just buy a used router, and run it as an AP.
I watched a guy on Youtube downloading most common drivers for antennas but he did not list them. Someone have a link to info ????
why would you want to do that ?
I agree with the statements already made about getting an AP or wifi router and using a that for wifi. A purpose-built wifi AP will have much better performance than any of the USB based devices that you are considering.