Did somebody say.... Axe-FX?
I run FRFR direct to FOH, so a poweramp won't be on my personal shopping list. However, there are a lot of options out there now at various price points for guys running a more conventional traditional route.
You have the ART SS stuff on the lower end, Matrix, and now the Retro Channel all out (or almost out). They range up to just over $1000 USD or so.
The tube stuff is covered - but Atomic's 50/50 rack mount wasn't mentioned. It's more affordable than the VHT that was.
The key for PRS if they go this route will be price point. Where do they fall? The features/price point balancing point will matter.