I choose the Raikage Barely, Raikage (A) is fast and strong. He also has the Lightning Armor.
Orochimaru can use his snakes to slow him down, but the Raikage (A) will overcome that. Orochimaru also has the Kusanagi (Grasscutter), which is a legendary sword that can cut through anything. Might not do much against the Raikage (A) Lightning Armor, but it will still leave the Raikage (A) sore. Using Edo Tensei is extreme as it needs preparation (body's and time) to assemble. Orochimaru also has his Regeneration Replacement technique, but overuse will deplete his chakra. Orochimaru has summon's, but with the Raikage's (A) strength I doubt they stand a chance. I'm not underestimating Orochimaru's strenght and abilities, I'm just stating facts.