If I'm not mistaked, the Pi Zero W is already clocked at 1Ghz, so your overclock will not considerably improve the system's performance.
For GBA, use lr-gpsp or gpsp as emulators, for SNES, use pisnes as emulator - this should get perform better on the Pi Zero W.
Contributions to the project are always appreciated, so if you would like to support us with a donation you can do so here.
Hosting provided by Mythic-Beasts. See the Hosting Information page for more information.