Create web-based CRM/ Inventory/ Job tracking softare

Hi there, I own a computer/ phone repair business and am currently a little disappointed at the software out there that's available to help me do my job efficiently. Most of the current offerings out there are either too simplistic, focus simply on field technicians or seem very difficult to navigate with lots of bugs. I feel most of them are made by someone very technically minded, leading them to be very unintuitive to use for most members of staff in the shop. Examples of current software: [login to view URL] [login to view URL] [login to view URL] [login to view URL] Im looking to build software that allows: -Ability to assign priority to repairs i.e. time constraints/ fast-track repairs -Ability to limit access to certain areas. So that staff can't see the financials. -Ability to flag an item/ ticket for manager. -Manage and track the progress of repairs, highlight those taking too long or those that are urgent, by means of colour coding in a table - this way the technician knows what needs to be repaired first. -Manage inventory of stock, auto-decrement stock items when invoices are written. -Search customers database easily, populate booking in forms automatically. -Rules for automatic escalations i.e any repair over 4 days old sends an email. -SMS/ Email alerts sent to customer to update repair progress -Convert web enquiries/ estimates in to tickets - Canned responses - save typing the same things many times - Decent responsive interface, almost every single one i've listed is awful to use on a phone, this makes it very slow for a field technician to use. - Integration to accounting software, Xero, Quickbooks etc - Integration to some form of mobile payment such as PayLeven, or ideally, iZettle. - Ability to send invoices online, again with a payment gateway such as iZettle. The closest comparison to what i'd like to have developed would be [login to view URL], but with less features. There are 3 or 4 ways of booking in work and multiple admin menus/ submenus, it's all far more complex than it needs to be. Imagine an interface like iZettle but with an invoicing tab, customer database tab, ticket/repairs tab and inventory tab. Please contact me if you think this is something you'd be able to develop. If you can have a look round Repairshopr and have a guess at how long something similar to that would take to build.