What suit can I take againts someone for slander and stalking

Sure you can try. But keep in mind you are going to be the one that has the entire burden of proof. You are going to also have to show real damages, beyond hurt feelings. Such as lost income, professional reputation damaged, etc. You are also going to have to prove they actually said it. And said it with malicious intent.

As far as stalking, have you reported it to the police, is there a restaining order. Stalking is actually a crime... you don't sue someone for it... they have to be charged and tried for it.

Be aware, as a lawyer will likely tell you. Be careful about what charges you make and what you say. The other person could be handed ammunition for a malicious prosecution suit that would then be a slam dunk if your case proves to not have merit.

Sometimes there are better solutions to a problem.