Multiple web Site with Shopping Cart MAGENTO

hi, i have bought 15-20 domains. i want to build a shopping cart to each of them. what i am thinking is to use the same database or products,so that i can manage it easily. but i may want to use different database for each store,to get more rankings in google. 1- to install e-commerce software to each site (15-20)domains 2- to install turkish language(15-20)domains 3- to install a template(15-20)domains 4- to make the desired configuration and changes(15-20)domains 5- to decide what to do and how to do it (which shopping cart ?,how will it be installed ? database settings ? ) i am waiting for your advices in number 5 and bids. NOTE. I prefer magento but other cars can be adviced too. this is a small budget project regards