Custom functions for ZOHO CRM/Projects/Desk

We require a number of custom functions to be written in Zoho. We require a FIXED Price quotation (please only post a price if this is your fixed & final price) to complete the below brief. The brief below is an overview of the work, exact details, including API Field Names etc will be provided once the project has been awarded.

The work will be managed using Zoho Projects and the person awarded will be asked to update the project tasks within Projects so progress can be tracked.
A Zoho Login will be created with Administrator priveledges
The system is live, therefore care must be taken in any changes made.
Due to previous bad experiences, we are looking to deal directly with the develop only, we will not accept working through an intermediary
We will happily full fund the cost of the project in escrow, but will not release final payment until the work is 100% complete.

CRM
We have created a custom function that creates a project & tasks from the creation of a Sales Order, we require minor amends to this
- Project Owner needs to be changed
- Task Description isn't included
- Add all Project internal users to the project
- Add Client Company & all Client Users from the Account matched from the Sales Order

CRM
We have a custom function that when a Quote is set to "Request Pricing" and a field is set to a User, a task is created within a specific project within PROJECTS, this is working, we just need this extending so the Task owner is set to match a field on the Quote within CRM

CRM
Create a Task & Sub tasks within an existing project from a Sales Order with a particular payment type.
The Task needs to be created within a MileStone that matches the name of the current month


DESK
- Create a task when a new ticket is created, within a project associated to the Account in DESK or within a generic project
- When Ticket is assigned an owner in Desk, set the Owner of the task in Projects
- When the ticket status changes in Desk, update Task status in Projects

BOOKS
We've had a custom function written by Zoho that creates a Draft invoice in Books when a Sales Order is created, this is working. We need the following modifications making
1. The invoice is being created in Books, but it's not using the "Unit Price" field in CRM, so the quote total was £400, yet the invoice created is £335. It seems to be taking the price from the price list, despite being told on Wednesday that if we enabled price lists, the code would use the Unit Price field in CRM.
2. We need the field "Client_Purchase_Order_Number" mapping to "Your PO Number" (cf_your_po_number) in books
3. Map CRM field "Quote_Reference" to Zoho books "Order Number" / Reference field
4. Write the invoice number created in Books back to CRM into "Xero_Final_Invoice_Number" field