Edit: removed the crappy demo. Put this in its place as it uses the same patch.
http://www.hammerscape.com/mp3/catacombs.mp3
I worked pretty hard last night to make a decent freeware-based guitar rig. This one has an odd little clean amp (which is disconnected from the main output by default) and two Marshall JCM900 amps set up in a complimentary manner, each panned hard L/R. You'll probably need to use the EQ at the end of the chain to compensate for your own guitar/pick-up configuration on the heavy amps. You might even want to experiment with a different EQ there since there are so many available to sculpt your tone.
The default setting sounded great using an Ibanez ARC300 with Seymour Duncan SH-2 jazz model™ humbuckers in both the bridge and middle position. It's somewhere between the brown tone of Van Halen's "Jamies Crying" and a typical kind of Dream Theater crunch. Tweak to taste. There's definitely headroom for more gain if you need it. So take a peak at both of the JCM900 gain settings as well as the final mixer stage (where I have it at 50% to avoid blasting someone's ears on startup).
Here's a screenshot of the rig to help you round up all the freeware. If it's not clear, all the amps are from GSuite. Visit http://www.simulanalog.org/
