Custom erp system

We want to add custom features to an already open source erp/crm software that will be cloud based just. We are a company that sells catering equipment for hotels, restaurant etc. Products such as proffesional fridges, kitchen, ovens etc. The way we do business is basiclly dropshipping. Most of the orders we take in are coming from phone sales and not through cart/checkout etc. The software we need is to be able to take a quotation that we have send to the client, turn it in order and automatically make a pretyped email to all the manufacturing companies whose products are included in the client's order and make the order to the company. We also want to be able to assign tasks to the other users and keep our clients database inside the software. In addition to that we want to keep track of all the client's activities. Also every time that the order changes state we want to send an automated email to the client informing him of the progress of his order. Additional information will be given for further undestanding of the project but the basic layout will be as described above. ***IMPORTANT We will not pay for the production of a completely new crm or erp software. We will only pay the custom features of an existing open source software that already exists in the market.