CLOUD WEBASED POINT OF SALE POS ERP SOFTWARE

I am looking a cloud based point of sale software for our Automotive Business we do both sales and service, we also barter with customers as well.. I want to pay sales team based upon commission on profit not total amount of sale. Also need it heavily geared towards inventory tracking and purchasing. Need it to be able to have 2 prices a lowest and a retail so sales team can negotiate the sale. Also need to be able to have item location in warehouse and be able to track between multiple locations/warehouses. Want to be able to run multiple business for the same system each with there own set of books for accounting, but be able to see inventory and other stores so it can be transferred or cross [login to view URL] get a more in dept description Please contact me for a list of functionality I require. I must be able to make sales when there is no internet connection and sync automatically when connection resumes also I must be sole owner to the software including coding, and script. Also whom ever does completes the job must be willing to make changes to it after job is completed in the future for updates.