The skinnier and taller the tires, the easier it will be to steer and at all speeds assuming all the previously mentioned parts of the steering system are in proper working order.
Without doing anything else to my truck other than installing 16" wheels instead of 15" wheels, and tires with a tread width of about 5" instead of 9" made the truck easy as pie to drive at all speeds. Prior to this it was impossible to steer at low speed and hard to steer at any speed above 10mph.
New shocks made handling perfect.
