Hammond power has found me a Y075PKCN3L0U (LINK) in stock.

It looks like what i need but i was unsure of whether or not I'd want to order the 'Neutral Kit' for it?

I've attached the schematics for the system that this transformer would be powering (just the 480VAC portion)

_XFMR help.pdf

the Hammond Power rep that I'm talking to is not really willing to give me any guidance...