Master no louder than -9 LUFS short-term at the loudest moments
(with True Peaks no higher than -1)
That's what Ian Shepherd says at least.
SimulAnalog guitar suite has a pretty decent Univibe free VST plugin.
Pulp-O-Mizer. Sonanaut. Polymer jerboa. In theory, you can use stereo or mono files for "3D" sounds in FMOD. But ther...