Any good ai sales agent tool software recommendation?

I run a growth marketing agency, i have decent number of clients in my country and few international clients so I am trying to find a good ai solution to automate the sales efforts - finding leads, finding their email ID, dropping a mail and connecting via linkedin.

is there any tool which can do this for $100-$150/month or is there any way i can make a tool like this inhouse which costs something similar?