If your looking for a rack and pinion google "No Limit Rack and Pinion" or check out this site:
http://www.nolimitparts.com/prodinfo.asp?number=PS-SA-I havnt done this myself but have read up on it quite a bit because im in the same boat looking for a power steering setup for my 57. It mounts to the axle and has a collapsible steering shaft that connects the R/P to the steering column to account for the up and down movement of the axle while your driving. Everything i've read has been pretty mixed opinions. Theres a lot of people that have used it and say that it works great and there are some that say no. IMHO i dont see a problem with the setup. Its a setup that was specifically designed for these pickups as well as fords of the same era. As far as it not being strong enough i wouldn't worry about it most truck now days use racks to steer an theyre much heavier. I know there's a guy on this site that has installed this setup an you can probably find him by doing a search.
There's always the toyota power steering box and the saginaw you can look into.
