replace/rebuild ECMs?

I may need to replace/rebuild my 2 ECMs, because they seem to have issues with hot weather.

I found these part numbers online but I’m not sure if they are correct or which one is ECU 1/2

  • 4F1910552GX
  • 4F1910552AX

Also found this site.

Any ideas, suggestions, warnings before I get too far into the process?