Best CRM that integrates with Quickbooks?

Basically the title.

Taking a leap of faith and decided to transition from corporate to a small business subcontractor with limited processes in place.

Small business currently utilizes quickbooks for their accounting and would like to keep using it. Looking to streamline anything possible really and I think setting up a good CRM would be a good start.

Looking to send out proposals, capture signatures, send out email campaigns, etc.

What CRM do you recommend? Are there any other integrations you enjoy other than quickbooks?

What streamlining processes have you implemented that was just a huge game changer?

Appreciate all help!