Best marketing & sales CRM that can grow with an early stage startup?

I just started working at a very small startup of 6 people. They have a huge marketing database of 100K+ contacts and 10K+ paying customers. We’re currently using Customer.io for marketing and like that it integrates with app usage, the segmentation abilities, SMS, push notifications, etc. on top of email.

However, we don’t currently have a sales CRM so I’ve been tasked with making a recommendation for something that will work now and that we can grow with (I’m in marketing).

Hubspot is pricey and we’ll lose some of the customer.io features mentioned above, but I like that it’s an all-in-one solution otherwise.

Are we better off sticking with customer.io and integrating with something like Pipedrive or Zoho for the sales side? I’ve never used anything besides Hubspot and Salesforce, so I’m not sure what the best option is.