ODoo Computer repair Module

General information for the business: We sell and repair computer for retail clients
Platform: OpenERP
Description of requirements/functionality: Currently Operation
we are using an external PC tracker and Quickbooks POS, Quickbooks Accounting.
Printer used: Epson TM88V with cash register
Our operation flow as follows:
Customer arrive, check in PC, collect a diagnostic fee, Bill and print out diagnostic fee charge in POS, after diagnostic, give quotation to customer, if customer accepts , we key in the repair items, during customer collection, we print out the remainder items that's not yet billed ( Example : if the repair only motherboard and diagnostic, we print out only the motherboard as the diagnostic already being previously billed.)

Your expertise to :
Create a Computer service repair work flow.
From customer pc/laptop/router/phone/tablet acquisition to customer deposit, separate billing,collection,payment.
Consist of:
Tab 1 : Customer PC acquisition with customer info and pc basic info. Printable out in 8cm width as per sample.
Tab 1.1 : PC repair stage with, pre-repair diagnose process(option to input a check box or comment), Technician recommendation(to be able to post into quotation), Customer decision(to be able to post into sales order), post-repair diagnose process(option to input a check box or comment)
Tab 2 : Overview : page 1 input info, page 1.1 info, Check box of call/SMS customer for collection as at checked date.
Please bring up suggestion if you have experience or idea.
Minimum modification to other modules.
GUI Is not required.

Our Observation so far :
I realize odoo can't collect cash or deposit before invoice.
In our operation, sometimes customer gives us a deposit.
Sometimes, they only do diagnostic test, we charge them diagnostic upfront.
Also in oDoo, the Quotation and sales order steps seems very long winded compare to quickbooks.
we hope to have the option to shorten the process. As most of our transaction takes place on the same day/time.

Other Reference
If you need a demo of our current PC tracker :
http://www.pcrepairtracker.com/repair/
username: demo
password: showthedemo

A reference of an existed Product By other source
https://bitbucket.org/apreimantas/pc_repair
Our Plan
If possible we would like to shift both the process tracking,sales and accounting into oDoo.
Due to accounting flow of POS, we would like to disintegrate POS from our operation.
Extra notes: