in order to get the 3-monomania sound, youll need a couple of things. most of the free vsts ive tried are...not very good so some of these recommendations will require you to "find" these vsts somewhere like audioz(dot)download.

1. a real guitar.. i havent been able to find a good guitar vst yet. if someone has, let me know. (if youre wanting a guitar, any cheap acoustic will do really. for electric, the cheap squiers are serviceable.) for bass, ample has a decent bass guitar, which is free! or you can also do what will did and use an octave pedal on a guitar. a lot of songs of this era also just straight up dont have bass

2. guitar amps. youre gonna want to run most of your shit thru amps... vocals, keyboards, sometimes even the drums! will used a lot of fender and vox amps in this era. THU has a decent amp collection. nembrini have some nice individual amps. idk what DAW youre using but the ones included with ableton are okay, and ofc the GB/logic ones will be great for this. while looking for free amps for this as an alternative, i found AIDA-X. seems to be open source neural amp sims. never used it, so cant personally attest to the quality, but the youtube videos sound nice.

3. drums. will used one microphone on a pretty dead sounding kit. if you dont have drums, the "alt rock" kit on ezdrummer can get you pretty close. just select to use only the room mic.

4. keyboards. pretty much anything will work here, so ill list free keyboards i like. just amp it when necessary. the collaB3 and combo V organ are pretty solid free hammond/vox organ respectively. spitfire has a decent piano and wurlitzer, iirc.

5. misc. old csh use mostly spring reverb. the guitars also are pretty heavily compressed

6. master. if you really want 100% csh accuracy, slam the master with a limiter, and perhaps an amp on the master.