Scope and estimate of Salesforce development vs from Scratch and Liferay vs WordPress

General information for the business: We are a commercial property business (offices etc) Description of requirements/functionality: We are looking for someone to create a document to help us decide: Whether to keep Salesforce and invest in developing it to suit our needs vs creating our own subset from scratch to suit our needs. It needs to have the whole project broken down in bite size chunks for the developers, plus effort estimates for each. Whether to use WordPress as a CMS for the Front-End or replace it with Liferay. Again it would need to have both options broken down in bite size chunks plus effort estimates for each. Specific technologies required: Salesforce, Java EE, APIs, microservices, WordPress, Liferay, Software Architecture, Technical Project Management OS requirements: Linux Extra notes: Preference will be given to European countries, South Africa or the US.