My concept has always been to ask where you get your sound.
Guitar amps/cabs are designed to effect the sound. A PA speaker, in theory, are supposed to reproduce without coloration.
For me, I get all my sound from the Duo and need something to reproduce without coloring and so a PA or studio monitors are the way to go. I use amp/cab sims inside the Duo.
However, PAs do have a sound and it would be best to test what works best in your application. I think the cheap PA speakers I have are pretty average and if I can make it sound good on these then I should be ok when plugging into other PA systems.
Others rely heavily on the color of a real amp/cab. The sims in the Duo do use more CPU than other plugins so depending on how involved the pedalboard is a hardware amp/cab may work better. Of course, this means that you are stuck with the hardware and if this is your tone then you will need to keep it (or something similar) all the time...
Where do you plug your headphones into? If using the Duo headphone jack then a PA may be a better way to go.
As for what PA to use... that is totally up to you...
It seems like the Laney gear is well made and cost effective... I see that Atomic and Friedman also make powered cabs for use with digital amp/cab sims.