Furst thing is ask Roland...
Yeah, I know that is pretty funny. 30-0-30 is 60v center tapped. and 159 VA is 158 watts or about 5 amps. SO most any tranny that spits out 24-30 volts a side at that sort of current would do.
What I would do:
Call Peavey and ask if they have any of the following power transformers in stock. Here is part number and model it served:
70516743 - 260C power amp
70518714 - 260D power amp
70518713 - Bandit 65
70516734 - Special (Verify this is not a typo for 16743 on the schematic)
70518714 - Special 130
All these transformers produce 42 volt rails at similar power levels. PV transformers are very sturdy and reliable.
Other than that, ANY SS amp with similar voltage rails can provide its powr tranny. I just happen to be most familiar with the PV line.