Back end management

See our website [login to view URL] - we are looking to upgrade this site, but in the first instance we urgently require a back end office management system to upload/download files / take on jobs, allocate to subcontractors and return to clients. What we do: (We provide EPC to estate agents and private landlords; we provide SAP ratings to commercial clients; we provide Code for sustainable homes for commercial clients == We also provide Electrical certificates and Gas Certificates). Ideally the system needs to be able to carry out the following: JP Energy - our end; Enter new client details creating their login/password Each client such as an estate agents chain will then have x number of branches, each branch needs to have logins so individual members of staff can place the orders online. Add DEA details & Login Add other supplier details and login Our clients Login; have a screen showing them their existing orders option to add order, they fill in address for property requiring EPC or other only fields with * being address1, City, Postcode. Drop down menu with 'services - Residential EPC / Commercial EPC / SAP / Code / Gas Cert / Electrical Cert Where to collect keys (tick box 'office' direct to property ' other with a text box) Submit (having ticked confirm terms). Order is now placed and emails me telling me of a new order. I then log in and view the order, I have a drop down menu to allocate to a supplier, the list of suppliers should be matched sequentially by who is the nearest supplier to the property address, from my list of suppliers. I then allocate to supplier of my choice, DEA or supplier receives the instruction by email. On the email link there should be a accept/decline link. when they click either I get an email back with confirmation either way and back office job is also auto updated without having to log in. The reason for this is that my suppliers are likely to be on the road and responding via their mobile device and this is much quicker than having to log into back end. When they do log in it will then ask for a date to be entered as to when it is booked for. Once the epc / service is completed - the supplier then logs in and uploads the document and their invoice for the job. The EPC/service should then automatically be uploaded to the clients back end and an auto email sent to the client telling them the EPC/service is complete with a link on the email that takes them to their account. Direct from here they can then download the document. I hope this makes sense, please let me know your price asap and turnaround time. NB - this back end will need to take on our colours and logo etc, but be mobile friendly so that it can be accessed by us, our suppliers and our clients from their smartphones etc, so we are looking for a simple and easy to use system, not overly complicated. big buttons are ideal.