Replacing the wheel bearings will probably not solve a rough ride. I recently replaced the wheel bearings on my brother in law's 2000 Explorer, they made a slight growling sound on turns. The front wheel bearings are part of the hub and are about $140 to $260 (depending on dealer or aftermarket) a side from the dealer and about an .9 hour each side to install. Rear wheel bearings are about $30 a side and and take about 1.3 to 1.5 hours total to replace both sides.
Shock absorbers have a greater effect on the way a vehicle rides.