Develop Magento Site

We are a vinyl graphics company and are launching a new product line/brand. I need a simple e-commerce site set-up to start off with. We usually use OSCommerce but would like this site to be Magento. We will select a theme to work with. We need the following abilities/features on this site. 1 - Ability to add product variables - size, color 2 - We will manage all content, products and data entry 3 - This site will need to work with our Paypal API for checkout 4 - Need the ability to create SEO specific landing pages 5 - Must be able to control URL/Directory structures for SEO 6 - Ability to add product tags and meta data for SEO Once this site is established we would then look at integrating a function that will allow users to design their own vinyl graphics products. We will provide hosting and already have our own domain. We can also provide the graphics needed to fill out the selected theme. We are looking at developing a relationship with a professional and dependable Magento developer as we have another site to develop and a very large OSCommerce site we would like to move to Magento. If you have question feel free to contact me. I can send links to site that sell competing products. We need this store set-up as soon as possible. We are looking for a detailed response to this RFP.