Gecko power supply transformer

OK folks, thanks for all of your timely and technically helpful
pointers on my Gecko G320 drivers power supply. I've settled a few
things already based on some of the insight and suggestions provided
from my first set of questions. But, I forgot one.
When sizing my toroidal transformer to go from nominally 120 VAC
(concede it can be 112 to 125 sporadically)into 36 VAC to the filter
caps and the bridge rectifier, am I to spec a volt-amp rating, and
which volts and amp numbers do I use and how do I use them?
thanks a lot in advance
Scott