Although Puppet Enterprise is typically deployed using master/agent Puppet,
puppet apply is still available on Puppet Enterprise nodes, and you can still use all of your existing open source workflows with Puppet Enterprise.
If you wish to use
puppet apply with the Puppet console, you will need to configure your nodes to send their reports to PuppetDB. You will also need to install the PuppetDB-terminus package on each node. You do not need to enable storeconfigs for reporting to work, which would eliminate any dependency on the console, PuppetDB, or PostgreSQL.
The Puppet console depends on PostgreSQL and the reporting system depends on PuppetDB. You will still need to install, manage, and configure these services, however they would not be a potential point of failure for you. You would have to sign a certificate for each node, since PuppetDB operates over HTTPS. You could however use a common certificate if you are not concerned about security.
The installers for the console, PostgreSQL, and PuppetDB depend on having a working master. The simplest way to satisfy these dependencies would be to perform an all-in-one installation. While these general instructions should be sufficient, you should be aware that I'm not a PuppetLabs employee, and unfortunately cannot provide more detailed step-by-step instructions. I encourage you to reach out to the Puppet Labs support team if you have questions.
With all of this said, I've found the Puppet Enterprise services to be incredibly reliable when sized correctly. If you're a licensed user of PE, you should reach out to the support team for assistance.