Agree with Shaun,

Another Hubspot partner agency owner here. On-boarded more than 12 clients to Hubspot and it worked for all of them.

Infusionsoft is doing good as well and they are in similar price range, however the Hubspot UX is much intuitive, it saves lots of time and also Hubspot CRM is one of the greatest CRM system I have ever used.

For lots of specific ecommerce integration Infusionsoft may work smoother, however when it comes to all in one marketing solution + sales and marketing alignment Hubspot is your best choice here and they get currently the 95% of the market share

Let me know what kind of integration you are planning, how your sales and marketing teams work together and I will be able to give much detailed guidance