Build a CRM and Internal Database Using AppSheet & App Scripts for Commercial Real Estate Brokerage

I own a commercial real estate company in Northern Virginia with about 3-4 employees. I am interested in hiring an expert with Google products to build an all-in-one CRM and marketing system exclusively using Google products.
My thought is to replace Buildout (a system we use with details below) by created an app in AppSheets that essentially has the same functions but uses all Google Apps (ie. Sheets, Sites, Forms, Docs, Slides, etc.). Below are current systems we use and their function:

Google Workspace (Business Standard edition):
Email: Gmail (@serafinre.com)
File Management: Google Drive
Documents: Google Docs
Marketing Brochures: Google Slides
Spreadsheet Templates: Google Sheets
Domain: serafinre.com
Contact Management: Google Contacts

Buildout (www.buildout.com: CRE CRM and Marketing Platform):
Lite CRM
Listing Management
Property Information (by fields)
Pipeline and Deal Stages
Commission Tracker
Plugins for Listings and Closed Inventory for Wordpress website
Document Generator