For that price range, you should be able to get a fully loaded gaming laptop!
Jenny100 has recommended referring to notebookreview.com for information and advice on laptops and I've used it several times. This page has their reviews for some multi media laptops. The one thing I would recommend is to get the best dedicated graphics card you can. I like the Dell XPS 15 on this page.
NotebookReview This Asus at Newegg has a Blu-Ray player and a higher screen resolution for watching movies. A cooling pad would be helpful for any laptop.
Asus N53 Jenny or Inland can answer your questions about the processor better than I can. But the 64-bit OS will be able to make use of more RAM, whereas the 32-bit is limited to a bit less than 4 GB of RAM.