Adding a front end to produce a retail store

We would like to utilise the facilities inside Infusionsoft while adding a front end from either WordPress or Shopify. Which solution is likely to be the easiest to achieve or are there trade-offs to take into account. Plus, who are the go to developers that I should asking for a quote?

By facilities I assume we’re speaking of integration options. I’m an ICD (I guess now it’s KCD…certified devveloper). Feel free to message me here or email to is not bad