A solid EmuELEC BIOS pack saves hours of hunting. Look for one that specifically lists "tested on EmuELEC 4.6+" and includes a .md5 checksum file for verification. Avoid packs over ~200MB unless they add disc-based system BIOS (which are small anyway).
While the EmuELEC BIOS pack is designed to work seamlessly with EmuELEC, issues can still arise: emuelec bios pack