Classifieds website (mobile friendly)

I would like to build a Simple buy and sell free classifieds website like [login to view URL],who is mobile friendly since most of the clients use smart phones,mostly andriod. this classifieds website will have wide different categories. Since most of our clients use mobile phone to access our website we would like to create a mobile version of our website wich will work like this: When the costumer comes in to the website he must have 2 options: BUY or SELL BUY: costumer must be directed to the main page where he will be able to see the different category's and the recently added products. the costumer can have the option to register. On the seller information page the costumer must be able to speed dial(if given a mobile number) Also on the seller information there must be a star rating where the costumers can rate the seller SELL: the seller must be able to come in the seller area have a simple registeration with either his email or facebook acount,choose a category and location he wants his products to be under,write brief description of the product contact detailes and add pictures either from his mobile phone or pc and post his product. The posted product must display on the frontpage under the recently added products and the choosen category. There must be also an option for own site for large sellers who have different products to display This will be paid option in the future,where it will be controled and granted acces by the admin. But now in the beginning it will be free for everybody to create own site within our marketplace. All in all the site must be easy to navigate and most importantly be mobile friendly.