noake,
A 1 1/2 HP 120V motor pulls around 20Amps The same in a 220V would be around 10Amps. I would run the 220V and at that distance you could get by with #12 but that is the MAX. Its slightly over the 3% allowed by code.

So if it were me I'd pull #10 AWG in and have some cushion. The nice thing about the conduit is the flexability of pull in pull out.

"If you aim at nothing you'll hit it every time"

Zig Ziglar