It is always difficult to try to compare because the venues,the loudness of the band and expectations are all different. Before the phil Jones I had an eden 450w traveller through an eden 2x10 and a 1x15 [along with various vintage acoustic amps]
In this period I also had a fender 100w valve amp and 4x10 neo cabinet which I recently sold purely because of weight issues and bought a PJB D400 and 2 C47 cabs. All of these amps have been able to do what I want them to and I would have thought that the C8 would do what you want,
The 8b is very easy to move, which was my orgnal reason for buying it, and as you say 2 C8s would be pretty awesome. You would need an amp that will handle down 2 ohms if you run 2 cabs because I think the c8s are 4 ohm.