54703 oscommerce site modifications

I have got an customized creloaded 6.1 site. I would like to find an expert to get those things done: 1) Add "define header" and "define footer" feature, which give me flexibility to add html codes in header area 2) In header area and footer area, it has 2 areas in which I can add two descriptions. These two description vary in different product and category pages. Each product or category has 2 fields , namely "A" and "B", I can put different content for "A' and "B" in admin area so header and footer in different pages are different. Be default, content of "A" and "B" are generated by combination of category name and product title. If I put something for A and B in admin area, it use my manually added texts. 3) I have installed "dynamic meta tag contribution" and would like to some modification on this contribution. Basically, this contribution automatically create page title, meta description and meta keywords. However, it disabled Header meta tag Controller contribution so I cannot edit page title etc in admin. I would like to modify it so that I can add/edit words in admin. And if I do not put anything in admin, it will auto generate page title, meta tags with that contribution. 4)Must work with easypopulate module. I suppose we will add 2 fields in product table and I can update product page with 2 fields added. Thanks