Simplify?

Woke up last week with an amazing SaaS idea, that I validated and already sold to two companies.

Now, I want to simplify my time to market. Here is what I need to create:

• Website/Homepage. Can be a one-pager + legal pages.
• The SaaS-app itself

Normally, I would code all of it from scratch, but this time I am looking at splitting both into two different sites. I am thinking of the following:

• Wordpress + Theme for the frontend. This gives me max flexibility in creating a blog and add plugins etc. to the front end without having to invest a lot of time on things that convert visitors into paying customers. It'll be easier to iterate and A/B test different versions without coding sessions.
• My own framework for the SaaS backend.

Now, this obviously has some drawbacks, as the frontend and backend will not look identical and that I won't have the ability to customise my frontend with information in regards to if a user is already logged in to the SaaS backend or not.

How do you tackle this or am I overcomplicating it? Adobe combines frontend and backend, Salesforce doesn't, Microsoft combines, Clearbit doesn't, etc.

Any suggestions or thoughts on Pro vs. Con?