I had a Helios, one of the first 50 or so. It sounded fantastic. I would go with the 100w, because you can always run it in JTM30 mode, which is what I did. Killer.
HOWEVER
This amp is sorta Bogner's SLO. It doesn't sound like an SLO, but it shares a similar philosophy - it gets that one unbelievable killer sound that makes you feel like you are on top of the mountain, and sorta facilitates other tones. But it is really about that one killer tone. If you need more flexibility, you have to plot out a solution because the amp isn't designed with that in mind.
Furthermore, I feel like the Helios has more modded metal-panel than Plexi in it. The attack is faster and tighter than say a '68. That will make it more adept at modern stuff, but if you are looking for Bogner's take on a 12000 this really isn't it.
Cool amp though. I did a video back in '14 that I think is pretty representative of how the amp sounds through a quality cab.