I plan to make multi channel driver to be able to control, say, eight windows each one with its own transparency level.
I'm trying to understand if this is a hobby project, commercial project or a single installation trying to go the low cost route. I would have different answers to each.
For commercial I would design a class-D amplifier with a high frequency output transformer and filter that can provide the voltage(s) you need.
For a hobby I would purchase a single class-D amplifier (perhaps on ebay) then drive a 120V/12V transformer backward.
Note: 60V => 60 * 1.414 = 85 volts peak.
You could generate a generate an 12v sinewave power the transformer and get
12V X 120 / 24 = 60v.
Remember this is RMS, you will have to pick input power to generate the 18 - 20 volt peak you will need
To make the whole system safe and reliable is not a trivial task.
In the US, "low voltage, aka Class 2" wiring can be used. This is doorbell, thermostat, low voltage LED usage and can use a simple wiring method.
At 60Vac I believe you are no longer Class 2 so your wiring requirements will be more stringent.
NEC Class 2Hope this helps.