Design and build of a online existing custom ordering system without payment facility

our web site is currently hosted on squarespace.com it seems to me that many of the features we want are already available on squarespace so experience within this system would be great.

we are looking for a company to design and build a web module/add on to allow exiting customers to log in and order consumables on line. We would also like a smart phone app for the same function. the same portal will allow customers to place a service call for their machines but this will be a second module after the on line

all our customers have an account facility so there is no payment facility necessary but we would like the system to generate a response confirmation email.

this is our existing web site www.poddrinks.co.uk once the payment module has been completed we would like to improve our web site as a separate project.