My memory is a bit rough on my fuzz researches but basically you want to excite odd harmonics and it will most likely look like a square wave.
Because of this, most fuzz effects aren’t friendly with complex chords, best with solo’s and power chords instead.
Software wise, there is a free fuzz pedal vst by Audio Damage
I know of only one spring reverb vst but it requires an iLok, but you can use the native chorus but for a vibrato effect instead which is also well suited for that western sound.
Fuzz vs Overdrive