Ton V. 's wireing schematic

[The Silver Bullet]

Here is a wire schematic developed by Tom V.

[resbum]

I will likely use this diagram as I am just starting to put things together..Would anyone care to comment on connecting a variac for speed control?
My guess is it needs to be AFTER the relays so the full 120V is available for them.

But, I am thinking I will need 2 variacs the way this is laid out.
Any ideas?

Also from my limited house wiring, it looks like I am using a 220 service for this. I am just spliting off separate 110 legs to the motors, correct?