i bet you can find a fan motor at a junkyard, or a power wheels mtor frm the power wheels car. you could also take the motor off a squrell cage blower and use compressor bleed air to drive it witch drives a belt to the pump
Power steering pumps take alot of juice to run. You're going to need about a 3HP motor. Very large.
How about just using a thin oil (0W-20) and using a low pressure (carb) fuel pump? This is what I am planning on. You don't want too much oil pressure to avoid drag on the shaft...