The big amps like yours will direct drive the 70 volt line, no out transformer needed.
An amp that will do at least 600 watts into 8 will make the 70 volt spec, you'll want to go a little
bigger for the line distance.
You can adjust the tap levels the further down line you get to balance the speaker levels.
Would this be just a one off thing or turn into an annual event, any chance they would want to have
year round music.
i dont know if this is a one-off , only time will tell
i just checked the PX 10 manual, and it turns out that the outputs is BTL coupled and can deliver 700w into 2 ohms
I might just work
. The good thing is that it contains DSP as well