Not sure if it is doable for your project or not but the people that swap 5.7 hemis sometimes use the Borgeson power steering box.
P/S Conversion 62-72 Mopar 1-1/8" Sector Shaft
Mike
My dad has a 55 Willy's wagon that had a 273 commando in it when he bought it. Drove it for years. Tons of torque and more than enough power for towing all the off road camping, hunting, fishing and other shenanigans he was up to. Go with the 273.
I was just starting to research this topic when I stumbled on this thread and an ebay seller with what seems like fair prices to me. http://stores.ebay.com/TEMCo-Industrial-Power-Supply
I was thinkg about the 1 or 0 gauge.
Mike