Website Customization & Redesign of few functionalities

We are having website called [login to view URL], we want to add some functionalities and customizing & fixing of few things, mazer functionalities like seller section customization and professional help documents and product data base system, currently its custom PHP, need to see whether any magento any ecommerce system to integrate, if anything feasible, we need that to integrate, Also we need filtering system to look at it and easy changes to catalog with excel down load and excel upload, sending daily report based on esquires. We need this on priority who can work 24/7 and give in very short type only bid for this. Also we need product database to build, its a data entry please quote based on per product basis, we need almost 25000 products at least. for this we need all HD quality images, specs and features and prices details.