I don't think Sasori poison can get to either Raikage, A or The Third Raikage.It took Sasuke's Chidori just to lay a tiny scratch on A during their battle, and I don't think Sasori's puppet swords have the penetration power of chidori.Not to mention, just catching the raikages is a hard task.Which Raikage? I'm guessing you mean the 4th and if so then Sasori may have a lot of issues due to A's speed. If he can somehow someway get his 3rd Kazekage puppet out before A completely busts him up then he has a chance to win with poison otherwise I just can't see him beating A.
Sasori doesn't need weapons for his poison.I don't think Sasori poison can get to either Raikage, A or The Third Raikage.It took Sasuke's Chidori just to lay a tiny scratch on A during their battle, and I don't think Sasori's puppet swords have the penetration power of chidori.Not to mention, just catching the raikages is a hard task.