Lead Generation for a HR & Payroll Company

We are a Southern CA-based HR company that has recently added payroll as an additional solution. We can compete with all of the big box companies (ADP/Paychex, etc.), but we need to develop a lead generation and appointment setting program to increase the number of leads flowing into our company. We have leads lists with both email and phone contacts, so what we're looking to discuss with the right partner is:

1. Appointments setting campaign
2. Lead nurturing campaigns for email
3. Lead generation to keep the pipeline going

We do have a limited starting budget, so we may need to do these things in stages, but we will continue to allocate more into marketing as we generate new business.