A good direct box will help get your signal to the PA.
The other side of this is the PA system and the sound person running it.
If it is a small venue, you'll have an easier time balancing the sound of your amp on stage with the PA.
But if this is the system your band is using:
The above system will need stage volume to help it along with mostly mid range and vocals being the most it will produce.
The larger PA system you use, it will also depend on how large a venue you play.
If it is an arena or outdoor gig, the PA will be your main connection with the audience and what you think they will hear won't necessarily be the case.
With your present PA, I would opt for having as good an amp as you can get for your steel and let this rather small PA system augment what your amp puts out.
Don't expect this system to faithfully produce anything more than a vocal with an acoustic guitar.
Your sound person is going to have to know how to make best use out this type of PA together with your stage amps and not as the only amp for your steel.
Unless you're playing a very small place will this system have enough power to present a full band.
That said, how will you monitor yourself if they want you to only go direct? The PA will be out in front of you and the band.
IEM's? Floor wedges?