The box swap should work with the F350, it used the same basic setup.
Any pump for a recirculating ball power steering will work. One from a R&P setup will not produce enough pressure. A pump from a land barge (Caddy, Lincoln, Imperial, etc may produce too much pressure. The Saginaw "canned ham" pump is a popular choice since it was used on many vehicles, certain Fords, Chrysler products and all GMs, and the pressure is easily adjusted with an inexpensive kit.
Updates to the linked article:
The Mid Fifty conversion pitman arm WILL fit the manual Toyota box as well as the power box.
There is a newly manufactured PS box available from Miid Fifty that bolts in directly and does not require a conversion mount.
The OEM Toyota boxes are getting a little harder to find, but they are still out there. The TOY box is nearly bulletproof, so don't be afraid to go with a used box.
Passionate about autocross racing!
1956 F100 Panel "GRACIE"
2007 Solstice GXP racer, the "KRAZED KANARY"
Third place finish 2009 SCCA National Championships