The ballasts I have, at least some of them, are multitap - I could run them on 220, 360 or 480 (or whatever the other voltages are).
But a watt is a watt. I still really don't know if there's a benefit to running one voltage over another.
Moot point anyhow now, looking at Home Depot though my jaw hit the floor when I saw the cost of copper. My plans to string 8 or 10 guage and use 20-amp breakers quickly dissipated. 14 guage and 15A will have to do, and this was already a dismaying cost for 200' of wire. Crazy.
Anyhow, so I more or less decided against running the 220V circuit on the spot then.
PS. Yeah, call the presses, I've been working on the tank project!

I'll try updating the build thread soon.