I had a JC120 back in the early 90s, fantastic amp, and currently have a JC90. The JC90 with the 10" speakers doesn't move as much air as the JC120 and doesn't seem to have as much low end. It is however, quite loud.
I also have a RKII and go back and forth almost weekly about selling the JC90. The RKII has great cleans and works well with my effects. I'd just hate to get rid of the JC90 and then want it again. There are a few things I regret selling in the past, the JC120 and my Rickenbacker 360/12 WB are two of them. What a combination those two were.
Also, compared to the RKII, the JC90 has a some hiss at lower volumes. Perhaps I am getting used to how dead quiet the RKII is. Let me know how your search for a JC120 goes, perhaps it will be on a day I am looking to get rid of the JC90.
I checked out the songs on your page, nice work.