Bead blasting is exactly like sand blasting, but you use "glass beads" instead of sand. The beads are almost the size of baking soda.
Bead blasting just provides a much smoother end result than does sand blasting. if you are just looking at wanting to remove the paint, and any rust that might have accumulated over the years, then bead blasting, and then repainting is the way to go.
Good luck.
P.S. you can get the glass beads from Granger's, or any sandblasting material supplier.