adding both are easy enough these days. for power brakes, start here
mustangsteve.com while his stuff is geared towards mustangs, a lot of his stuff can be easily adapted to your maverick as well.
as for power steering, start here
Ford Maverick .com they are a maverick forum, and have articles regarding mavericks as well.
you can also try this place, they have a lot of good parts available as well
1972 Ford Maverick Parts Ford Parts, Classic Car Parts, Truck Parts and Services by Auto Krafters-Mustang Auto Parts Too!