Oh dear, let’s forget about the VM solution. VirtualBox’ VESA emulation is incompatible with GTA.
I think running the game on Windows could be a good option for most.
Concerning the 3DFX: If you really want it to work, you’ll have to put the GLIDE2X.OVL into the GTADOS directory, not the GTA directory. I’m not sure you were trying that. I’ve never used Glide wrapper, no idea wher the DLL goes 🙂