What's the best software for a mixed drip campaign/phone call lead system?

I am looking for a marketing automation platform that integrates with a CRM to perform the following drip campaign/phone call mixed workflow. What are my options?

The workflow

1. User enters lead data into CRM and drip email 1 is distributed.
2. After 3 days, CRM prompts user to call lead.
2a. If call is not completed within 24 hours, system sends out drip email 2a.
2b. If call is completed within 24 hours and lead status is not changed, i.e., no phone contact was made, system sends out drip email 2b. (Ideally, the call is made from within the CRM so that the system knows automatically to send out drip email 2b instead of requiring the user to mark the call task as complete).
3. After another 3 days, CRM prompts user to call lead.
3a. If call is not completed within 24 hours, system sends out drip email 3a.
3b. If call is completed within 24 hours and lead status is not changed, i.e., no phone contact was made, system sends out drip email 3b.
4. After another 3 days, user is transferred to a different workflow (for monthly email followup) if lead status remains unchanged.