Furniture ERP Development

Need to build an ERP for Furniture Company where : We manage our clients - add, edit, delete Add projects for clients Add documents related to project - Quotation, PO Mark payments due date for the project Add products sourced for the project or vendors Add comments for the project and emails related to project should go automatically in there. Should have the option to reply emails from there too. Add project add-ons or enhancemenet settled - Seperate quotation, PO and payment dates will be added for add-ons Multiple projects can be added for one client Total client worth - sum of all the project value settled with client, how much is received and what is pending Project Flow - I first want to finalise Layout of the project. I want a super easy UI and everything at one place. System architecture is most important. Once finalised, we go with development I have attached project detail scope, you can check that too.