price comparison or product datafeed backend interface and search function

Hello, we are searching again for a longtime partnership with a coder who can handle bigger xml webservices and has a feeling to work with large product datafeeds and search functions. We run an xml webservices based affiliate website, but sometimes real shops asks us to add also their products and for this we search a solution and esp. a coder who has done similar. So: We search a backend where single shops can add, upload and change datafeeds. It should be exist a cron possibility and to use for each shop different import routines (depending on the shop export they use). After setup the system must run automatic with differnet user logins. It mus be combinated with a click counter so shops may be optional per click and in best case directly with outputs for invoices or a good format to create them easy. If you have done similar and you have directly a solution how to search and sort the data, great, let us know. You MUST be able to show something similar. Stupid standart answers like "we do all and fast and cheap" (sorry, but to talk to such people is wasted time) will be deleted without answer. So in small words: we are searching for a backend and admin area of a smaller price comparison. Regards Frank