conversion of website to wordpress based one

I have a technical website hosting civil engg related articles & construction softwares. The website is built using a readymade custom css/html/php template/script. I want to convert it to a suitable wordpress theme. The requirements are:- 1. Professional appearance 2. Ease of navigation (with menus, breadcrumbs) 3. optimized layout of adsense ads - with well blended colour scheme 4. Basic SEO optimization 5. Maintaining a consistent layout in website (including where external scripts like Q-A, Coppermine, disqus, sharethis are involved) 6. Provision for social networking buttons, rss feeds 7. Existing scripts should not get compromised 8. Design of sales pages 9. Content migration