When you extract the rexagames.com.rar folder and run gta_sa.exe, you will likely encounter:
Here is the step-by-step fix to make this specific repack work like a retail copy.
Created by Silent, this fixes over 100 bugs specific to v1.0:
If you get a CRC error on gta3.img or audio/streams, download a specific replacement file from a modding database rather than re-downloading the entire 4GB RAR.
Because the RexaGames repack often uses OGG compression for radio stations, you need the Radio Restorer.